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SMD code search: identify a part by its marking

No part printed B is recorded in X1SON. 6 printed with a similar-looking code.

No part printed B is recorded in X1SON

Not sure which one you have?

Answer up to 4 quick questions and these 19 parts are ranked, with a meter test that settles it. It works on a dead part too.

19 parts have no package on record. Nothing rules them out, so they stay.

  • AON1606MOSFET, Alpha & Omega Semiconductor
    What it is
    MOSFET
    Maker
    Alpha & Omega Semiconductor
    Package
    Not recorded
    Pins
    Not recorded
    Details
    Low-voltage (12-30 V) MOSFET
    Source
    From the manufacturer's datasheet

    Is it dead?

    Diode range, part lifted. Test drain to source first, then short gate to source and test again.

    Working, it reads

    One way between drain and source reads about 0.4 to 0.9 V, the body diode, and the other way open. The gate reads open to both other pins.

    Dead, it reads

    • Drain to source the same both ways, near 0 V with a continuous beep, and still so after shorting gate to source: shorted. The classic failure.
    • The gate reads low to source or drain: gate shorted.
    • No body diode at all: failed open.
    On the board
    the gate usually has a resistor to the source, which reads as that resistor and is not a fault. Lift a leg to be sure.
    Compare:
    If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
    Watch for:
    The diode range can charge the gate enough to turn the part on, and then drain to source reads near 0 both ways on a good part. Short gate to source and test again before you condemn it.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor AON1606, opens in a new tab
  • AON1606LMOSFET, Alpha & Omega Semiconductor
    What it is
    MOSFET
    Maker
    Alpha & Omega Semiconductor
    Package
    Not recorded
    Pins
    Not recorded
    Details
    Low-voltage (12-30 V) MOSFET
    Source
    From the manufacturer's datasheet

    Is it dead?

    Diode range, part lifted. Test drain to source first, then short gate to source and test again.

    Working, it reads

    One way between drain and source reads about 0.4 to 0.9 V, the body diode, and the other way open. The gate reads open to both other pins.

    Dead, it reads

    • Drain to source the same both ways, near 0 V with a continuous beep, and still so after shorting gate to source: shorted. The classic failure.
    • The gate reads low to source or drain: gate shorted.
    • No body diode at all: failed open.
    On the board
    the gate usually has a resistor to the source, which reads as that resistor and is not a fault. Lift a leg to be sure.
    Compare:
    If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
    Watch for:
    The diode range can charge the gate enough to turn the part on, and then drain to source reads near 0 both ways on a good part. Short gate to source and test again before you condemn it.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor AON1606L, opens in a new tab
  • AOZ8S204BLS-03ESD protection diode, Alpha & Omega Semiconductor
    What it is
    ESD protection diode
    Maker
    Alpha & Omega Semiconductor
    Package
    Not recorded
    Pins
    Not recorded
    Details
    ESD protection for high-speed interfaces
    Source
    From the manufacturer's datasheet

    Is it dead?

    Diode range, from the protected line to ground, part lifted if you can.

    Working, it reads

    A one-way part reads about 0.6 to 0.8 V forward and open in reverse. A two-way part reads open both ways. Arrays with several lines read as the datasheet's diagram draws them.

    Dead, it reads

    • From the line to ground, the same reading both ways, near 0 V with a continuous beep: shorted.
    • A reading both ways on a one-way part: leaky.
    • A one-way part open both ways: failed open.
    On the board
    , a line reading shorted to ground can be this part or anything else on that line. Lift it: if the short goes with it, it has failed.
    Compare:
    The same part on the next line or connector pin is the healthy reading to compare with.
    Watch for:
    A two-way part reads open both ways when it is good, exactly like one that has failed open. The meter cannot tell them apart; an identical part on the next line can.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor AOZ8S204BLS-03, opens in a new tab
  • AOZ8S204BLS-05ESD protection diode, Alpha & Omega Semiconductor
    What it is
    ESD protection diode
    Maker
    Alpha & Omega Semiconductor
    Package
    Not recorded
    Pins
    Not recorded
    Details
    ESD protection for high-speed interfaces
    Source
    From the manufacturer's datasheet

    Is it dead?

    Diode range, from the protected line to ground, part lifted if you can.

    Working, it reads

    A one-way part reads about 0.6 to 0.8 V forward and open in reverse. A two-way part reads open both ways. Arrays with several lines read as the datasheet's diagram draws them.

    Dead, it reads

    • From the line to ground, the same reading both ways, near 0 V with a continuous beep: shorted.
    • A reading both ways on a one-way part: leaky.
    • A one-way part open both ways: failed open.
    On the board
    , a line reading shorted to ground can be this part or anything else on that line. Lift it: if the short goes with it, it has failed.
    Compare:
    The same part on the next line or connector pin is the healthy reading to compare with.
    Watch for:
    A two-way part reads open both ways when it is good, exactly like one that has failed open. The meter cannot tell them apart; an identical part on the next line can.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor AOZ8S204BLS-05, opens in a new tab
  • AOZ8S322UD2-03ESD protection diode, Alpha & Omega Semiconductor
    What it is
    ESD protection diode
    Maker
    Alpha & Omega Semiconductor
    Package
    Not recorded
    Pins
    Not recorded
    Details
    ESD protection for high-speed interfaces
    Source
    From the manufacturer's datasheet

    Is it dead?

    Diode range, from the protected line to ground, part lifted if you can.

    Working, it reads

    A one-way part reads about 0.6 to 0.8 V forward and open in reverse. A two-way part reads open both ways. Arrays with several lines read as the datasheet's diagram draws them.

    Dead, it reads

    • From the line to ground, the same reading both ways, near 0 V with a continuous beep: shorted.
    • A reading both ways on a one-way part: leaky.
    • A one-way part open both ways: failed open.
    On the board
    , a line reading shorted to ground can be this part or anything else on that line. Lift it: if the short goes with it, it has failed.
    Compare:
    The same part on the next line or connector pin is the healthy reading to compare with.
    Watch for:
    A two-way part reads open both ways when it is good, exactly like one that has failed open. The meter cannot tell them apart; an identical part on the next line can.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor AOZ8S322UD2-03, opens in a new tab
  • AOZ8829ADI-05ESD protection diode, Alpha & Omega Semiconductor
    What it is
    ESD protection diode
    Maker
    Alpha & Omega Semiconductor
    Package
    Not recorded
    Pins
    Not recorded
    Details
    ESD protection for high-speed interfaces
    Source
    From the manufacturer's datasheet

    Is it dead?

    Diode range, from the protected line to ground, part lifted if you can.

    Working, it reads

    A one-way part reads about 0.6 to 0.8 V forward and open in reverse. A two-way part reads open both ways. Arrays with several lines read as the datasheet's diagram draws them.

    Dead, it reads

    • From the line to ground, the same reading both ways, near 0 V with a continuous beep: shorted.
    • A reading both ways on a one-way part: leaky.
    • A one-way part open both ways: failed open.
    On the board
    , a line reading shorted to ground can be this part or anything else on that line. Lift it: if the short goes with it, it has failed.
    Compare:
    The same part on the next line or connector pin is the healthy reading to compare with.
    Watch for:
    A two-way part reads open both ways when it is good, exactly like one that has failed open. The meter cannot tell them apart; an identical part on the next line can.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor AOZ8829ADI-05, opens in a new tab
  • BAS16-03WSwitching diode, Infineon
    What it is
    Switching diode
    Maker
    Infineon
    Package
    Not recorded
    Pins
    Not recorded
    Source
    From the manufacturer's datasheet

    Is it dead?

    Diode range, part lifted or one leg off the pad. Red probe on the anode.

    Working, it reads

    About 0.5 to 0.8 V anode to cathode, and open the other way. Small switching diodes read about 0.6 to 0.7 V; large rectifiers can read a little lower.

    Dead, it reads

    • The same reading both ways round, near 0 V with a continuous beep or the same middling value: shorted.
    • Open both ways: failed open.
    • A reading the wrong way round as well: leaky.
    On the board
    this is a first look only: the meter reads every path between those pins, and a short can be a neighbour. Lift one leg before you condemn it.
    Compare:
    If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
    Watch for:
    A three-pin body can hold two diodes. With a common pin they read two junctions from that pin, just like a transistor; in series they read two drops end to end. Test each pair the datasheet names.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor BAS16-03W, opens in a new tab
  • BAT15-098LRHSchottky diode, Infineon
    What it is
    Schottky diode
    Maker
    Infineon
    Package
    Not recorded
    Pins
    Not recorded
    Source
    From the manufacturer's datasheet

    Is it dead?

    Diode range, part lifted or one leg off the pad. Red probe on the anode.

    Working, it reads

    About 0.15 to 0.45 V anode to cathode, roughly half a silicon diode, and open the other way.

    Dead, it reads

    • The same reading both ways round, near 0 V with a continuous beep or the same middling value: shorted.
    • A reading the wrong way round as well: leaky.
    • Open both ways: failed open.
    On the board
    this is a first look only: the meter reads every path between those pins, and a short can be a neighbour. Lift one leg before you condemn it.
    Compare:
    If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
    Watch for:
    A large Schottky can read about 0.1 V forward and beep like a short, and leaks a little the wrong way when good, more when warm. It is shorted only if it reads the same both ways. Measure it cold, beside an identical cold one.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor BAT15-098LRH, opens in a new tab
  • BB555-02VInfineon
    What it is
    Not recorded
    Maker
    Infineon
    Package
    Not recorded
    Pins
    Not recorded
    Source
    From the manufacturer's datasheet

    Is it dead?

    Diode range and ohms range, part lifted.

    Working, it reads

    Depends on what it is. The datasheet, or an identical part, says.

    Dead, it reads

    • Between two pins, the same reading both ways, near 0 V with a continuous beep: shorted.
    • Open between every pair of pins: failed open, or a part that reads open when working.
    On the board
    this is a first look only: the meter reads every path between those pins, and a short can be a neighbour. Lift one leg before you condemn it.
    Compare:
    If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor BB555-02V, opens in a new tab
  • ESD5V0AE1ESD protection diode, JSCJ
    What it is
    ESD protection diode
    Maker
    JSCJ
    Package
    Not recorded
    Pins
    Not recorded
    Details
    ESD protection diode, VRWM 5 V
    Source
    From the manufacturer's datasheet

    Is it dead?

    Diode range, from the protected line to ground, part lifted if you can.

    Working, it reads

    A one-way part reads about 0.6 to 0.8 V forward and open in reverse. A two-way part reads open both ways. Arrays with several lines read as the datasheet's diagram draws them.

    Dead, it reads

    • From the line to ground, the same reading both ways, near 0 V with a continuous beep: shorted.
    • A reading both ways on a one-way part: leaky.
    • A one-way part open both ways: failed open.
    On the board
    , a line reading shorted to ground can be this part or anything else on that line. Lift it: if the short goes with it, it has failed.
    Compare:
    The same part on the next line or connector pin is the healthy reading to compare with.
    Watch for:
    A two-way part reads open both ways when it is good, exactly like one that has failed open. The meter cannot tell them apart; an identical part on the next line can.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor ESD5V0AE1, opens in a new tab
  • ESD217-B1-02ELESD protection diode, Infineon
    What it is
    ESD protection diode
    Maker
    Infineon
    Package
    Not recorded
    Pins
    Not recorded
    Source
    From the manufacturer's datasheet

    Is it dead?

    Diode range, from the protected line to ground, part lifted if you can.

    Working, it reads

    A one-way part reads about 0.6 to 0.8 V forward and open in reverse. A two-way part reads open both ways. Arrays with several lines read as the datasheet's diagram draws them.

    Dead, it reads

    • From the line to ground, the same reading both ways, near 0 V with a continuous beep: shorted.
    • A reading both ways on a one-way part: leaky.
    • A one-way part open both ways: failed open.
    On the board
    , a line reading shorted to ground can be this part or anything else on that line. Lift it: if the short goes with it, it has failed.
    Compare:
    The same part on the next line or connector pin is the healthy reading to compare with.
    Watch for:
    A two-way part reads open both ways when it is good, exactly like one that has failed open. The meter cannot tell them apart; an identical part on the next line can.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor ESD217-B1-02EL, opens in a new tab
  • ESDM5V0AE1ESD protection diode, JSCJ
    What it is
    ESD protection diode
    Maker
    JSCJ
    Package
    Not recorded
    Pins
    Not recorded
    Details
    ESD protection diode, VRWM 5 V
    Source
    From the manufacturer's datasheet

    Is it dead?

    Diode range, from the protected line to ground, part lifted if you can.

    Working, it reads

    A one-way part reads about 0.6 to 0.8 V forward and open in reverse. A two-way part reads open both ways. Arrays with several lines read as the datasheet's diagram draws them.

    Dead, it reads

    • From the line to ground, the same reading both ways, near 0 V with a continuous beep: shorted.
    • A reading both ways on a one-way part: leaky.
    • A one-way part open both ways: failed open.
    On the board
    , a line reading shorted to ground can be this part or anything else on that line. Lift it: if the short goes with it, it has failed.
    Compare:
    The same part on the next line or connector pin is the healthy reading to compare with.
    Watch for:
    A two-way part reads open both ways when it is good, exactly like one that has failed open. The meter cannot tell them apart; an identical part on the next line can.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor ESDM5V0AE1, opens in a new tab
  • IRLML2803N-channel MOSFET, Infineon
    What it is
    N-channel MOSFET
    Maker
    Infineon
    Package
    Not recorded
    Pins
    Not recorded
    Details
    30V Single N-Channel Power MOSFET in a Micro 3 package
    Source
    From the manufacturer's datasheet

    Is it dead?

    Diode range, part lifted. Test drain to source first, then short gate to source and test again.

    Working, it reads

    Red probe on the source, black on the drain: about 0.4 to 0.9 V, the body diode. Open the other way. The gate reads open to both other pins, both ways.

    Dead, it reads

    • Drain to source the same both ways, near 0 V with a continuous beep, and still so after shorting gate to source: shorted. The classic failure.
    • The gate reads low to source or drain: gate shorted. Often all three pins end up shorted together.
    • No body diode at all: failed open.
    On the board
    the gate usually has a resistor to the source, so gate to source reads that resistor, which is not a fault. A drain short can be the load. Lift a leg to be sure.
    Compare:
    If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
    Watch for:
    The diode range can charge the gate enough to turn the part on, and then drain to source reads near 0 both ways on a good part. Short gate to source and test again before you condemn it.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor IRLML2803, opens in a new tab
  • PJSD05TMESD protection diode, Panjit
    What it is
    ESD protection diode
    Maker
    Panjit
    Package
    Not recorded
    Pins
    Not recorded
    Source
    From the manufacturer's datasheet

    Is it dead?

    Diode range, from the protected line to ground, part lifted if you can.

    Working, it reads

    A one-way part reads about 0.6 to 0.8 V forward and open in reverse. A two-way part reads open both ways. Arrays with several lines read as the datasheet's diagram draws them.

    Dead, it reads

    • From the line to ground, the same reading both ways, near 0 V with a continuous beep: shorted.
    • A reading both ways on a one-way part: leaky.
    • A one-way part open both ways: failed open.
    On the board
    , a line reading shorted to ground can be this part or anything else on that line. Lift it: if the short goes with it, it has failed.
    Compare:
    The same part on the next line or connector pin is the healthy reading to compare with.
    Watch for:
    A two-way part reads open both ways when it is good, exactly like one that has failed open. The meter cannot tell them apart; an identical part on the next line can.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor PJSD05TM, opens in a new tab
  • PS140M-D32ESD protection diode, Panjit
    What it is
    ESD protection diode
    Maker
    Panjit
    Package
    Not recorded
    Pins
    Not recorded
    Source
    From the manufacturer's datasheet

    Is it dead?

    Diode range, from the protected line to ground, part lifted if you can.

    Working, it reads

    A one-way part reads about 0.6 to 0.8 V forward and open in reverse. A two-way part reads open both ways. Arrays with several lines read as the datasheet's diagram draws them.

    Dead, it reads

    • From the line to ground, the same reading both ways, near 0 V with a continuous beep: shorted.
    • A reading both ways on a one-way part: leaky.
    • A one-way part open both ways: failed open.
    On the board
    , a line reading shorted to ground can be this part or anything else on that line. Lift it: if the short goes with it, it has failed.
    Compare:
    The same part on the next line or connector pin is the healthy reading to compare with.
    Watch for:
    A two-way part reads open both ways when it is good, exactly like one that has failed open. The meter cannot tell them apart; an identical part on the next line can.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor PS140M-D32, opens in a new tab
  • SS14MSchottky diode, Taiwan Semiconductor
    What it is
    Schottky diode
    Maker
    Taiwan Semiconductor
    Package
    Not recorded
    Pins
    Not recorded
    Details
    Rectifier schottky
    Source
    From the manufacturer's datasheet

    Is it dead?

    Diode range, part lifted or one leg off the pad. Red probe on the anode.

    Working, it reads

    About 0.15 to 0.45 V anode to cathode, roughly half a silicon diode, and open the other way.

    Dead, it reads

    • The same reading both ways round, near 0 V with a continuous beep or the same middling value: shorted.
    • A reading the wrong way round as well: leaky.
    • Open both ways: failed open.
    On the board
    this is a first look only: the meter reads every path between those pins, and a short can be a neighbour. Lift one leg before you condemn it.
    Compare:
    If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
    Watch for:
    A large Schottky can read about 0.1 V forward and beep like a short, and leaks a little the wrong way when good, more when warm. It is shorted only if it reads the same both ways. Measure it cold, beside an identical cold one.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor SS14M, opens in a new tab
  • SS14MHSchottky diode, Taiwan Semiconductor
    What it is
    Schottky diode
    Maker
    Taiwan Semiconductor
    Package
    Not recorded
    Pins
    Not recorded
    Details
    Rectifier schottky
    Source
    From the manufacturer's datasheet

    Is it dead?

    Diode range, part lifted or one leg off the pad. Red probe on the anode.

    Working, it reads

    About 0.15 to 0.45 V anode to cathode, roughly half a silicon diode, and open the other way.

    Dead, it reads

    • The same reading both ways round, near 0 V with a continuous beep or the same middling value: shorted.
    • A reading the wrong way round as well: leaky.
    • Open both ways: failed open.
    On the board
    this is a first look only: the meter reads every path between those pins, and a short can be a neighbour. Lift one leg before you condemn it.
    Compare:
    If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
    Watch for:
    A large Schottky can read about 0.1 V forward and beep like a short, and leaks a little the wrong way when good, more when warm. It is shorted only if it reads the same both ways. Measure it cold, beside an identical cold one.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor SS14MH, opens in a new tab
  • VCAN33A2-HT5ESD protection diode, Vishay
    What it is
    ESD protection diode
    Maker
    Vishay
    Package
    Not recorded
    Pins
    Not recorded
    Details
    Bidirectional Symmetrical (BiSy) Low Capacitance, Dual-Line ESD Protection Diode in DFN1110-3A
    Source
    From the manufacturer's datasheet

    Is it dead?

    Diode range, from the protected line to ground, part lifted if you can.

    Working, it reads

    A one-way part reads about 0.6 to 0.8 V forward and open in reverse. A two-way part reads open both ways. Arrays with several lines read as the datasheet's diagram draws them.

    Dead, it reads

    • From the line to ground, the same reading both ways, near 0 V with a continuous beep: shorted.
    • A reading both ways on a one-way part: leaky.
    • A one-way part open both ways: failed open.
    On the board
    , a line reading shorted to ground can be this part or anything else on that line. Lift it: if the short goes with it, it has failed.
    Compare:
    The same part on the next line or connector pin is the healthy reading to compare with.
    Watch for:
    A two-way part reads open both ways when it is good, exactly like one that has failed open. The meter cannot tell them apart; an identical part on the next line can.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor VCAN33A2-HT5, opens in a new tab
  • VCUT0714A-HD1ESD protection diode, Vishay
    What it is
    ESD protection diode
    Maker
    Vishay
    Package
    Not recorded
    Pins
    Not recorded
    Details
    Bidirectional Asymmetrical (BiAs) Single Line ESD Protection Diode in LLP1006-2L
    Source
    From the manufacturer's datasheet

    Is it dead?

    Diode range, from the protected line to ground, part lifted if you can.

    Working, it reads

    A one-way part reads about 0.6 to 0.8 V forward and open in reverse. A two-way part reads open both ways. Arrays with several lines read as the datasheet's diagram draws them.

    Dead, it reads

    • From the line to ground, the same reading both ways, near 0 V with a continuous beep: shorted.
    • A reading both ways on a one-way part: leaky.
    • A one-way part open both ways: failed open.
    On the board
    , a line reading shorted to ground can be this part or anything else on that line. Lift it: if the short goes with it, it has failed.
    Compare:
    The same part on the next line or connector pin is the healthy reading to compare with.
    Watch for:
    A two-way part reads open both ways when it is good, exactly like one that has failed open. The meter cannot tell them apart; an identical part on the next line can.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor VCUT0714A-HD1, opens in a new tab
6 more parts are printed with a code easy to misread as B: none in X1SON, 6 with no package on record

Printed with a code easy to misread

One character differs, and it is one that is easy to confuse under a lamp. The odd one out is marked on each.

6 parts have no package on record. Nothing rules them out, so they stay.

  • AOZ8S503BDS-05printed 8ESD protection diode, Alpha & Omega Semiconductor

    Printed 8 on the part. Easy to misread as B. Check that character with a loupe before you order anything.

    What it is
    ESD protection diode
    Maker
    Alpha & Omega Semiconductor
    Package
    Not recorded
    Pins
    Not recorded
    Source
    From the manufacturer's datasheet

    Is it dead?

    Diode range, from the protected line to ground, part lifted if you can.

    Working, it reads

    A one-way part reads about 0.6 to 0.8 V forward and open in reverse. A two-way part reads open both ways. Arrays with several lines read as the datasheet's diagram draws them.

    Dead, it reads

    • From the line to ground, the same reading both ways, near 0 V with a continuous beep: shorted.
    • A reading both ways on a one-way part: leaky.
    • A one-way part open both ways: failed open.
    On the board
    , a line reading shorted to ground can be this part or anything else on that line. Lift it: if the short goes with it, it has failed.
    Compare:
    The same part on the next line or connector pin is the healthy reading to compare with.
    Watch for:
    A two-way part reads open both ways when it is good, exactly like one that has failed open. The meter cannot tell them apart; an identical part on the next line can.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor AOZ8S503BDS-05, opens in a new tab
  • AOZ8S513BDS-05printed 8ESD protection diode, Alpha & Omega Semiconductor

    Printed 8 on the part. Easy to misread as B. Check that character with a loupe before you order anything.

    What it is
    ESD protection diode
    Maker
    Alpha & Omega Semiconductor
    Package
    Not recorded
    Pins
    Not recorded
    Source
    From the manufacturer's datasheet

    Is it dead?

    Diode range, from the protected line to ground, part lifted if you can.

    Working, it reads

    A one-way part reads about 0.6 to 0.8 V forward and open in reverse. A two-way part reads open both ways. Arrays with several lines read as the datasheet's diagram draws them.

    Dead, it reads

    • From the line to ground, the same reading both ways, near 0 V with a continuous beep: shorted.
    • A reading both ways on a one-way part: leaky.
    • A one-way part open both ways: failed open.
    On the board
    , a line reading shorted to ground can be this part or anything else on that line. Lift it: if the short goes with it, it has failed.
    Compare:
    The same part on the next line or connector pin is the healthy reading to compare with.
    Watch for:
    A two-way part reads open both ways when it is good, exactly like one that has failed open. The meter cannot tell them apart; an identical part on the next line can.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor AOZ8S513BDS-05, opens in a new tab
  • AOZ8839DI-05printed 8ESD protection diode, Alpha & Omega Semiconductor

    Printed 8 on the part. Easy to misread as B. Check that character with a loupe before you order anything.

    What it is
    ESD protection diode
    Maker
    Alpha & Omega Semiconductor
    Package
    Not recorded
    Pins
    Not recorded
    Details
    ESD protection for high-speed interfaces
    Source
    From the manufacturer's datasheet

    Is it dead?

    Diode range, from the protected line to ground, part lifted if you can.

    Working, it reads

    A one-way part reads about 0.6 to 0.8 V forward and open in reverse. A two-way part reads open both ways. Arrays with several lines read as the datasheet's diagram draws them.

    Dead, it reads

    • From the line to ground, the same reading both ways, near 0 V with a continuous beep: shorted.
    • A reading both ways on a one-way part: leaky.
    • A one-way part open both ways: failed open.
    On the board
    , a line reading shorted to ground can be this part or anything else on that line. Lift it: if the short goes with it, it has failed.
    Compare:
    The same part on the next line or connector pin is the healthy reading to compare with.
    Watch for:
    A two-way part reads open both ways when it is good, exactly like one that has failed open. The meter cannot tell them apart; an identical part on the next line can.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor AOZ8839DI-05, opens in a new tab
  • BBY58-02Vprinted 8Infineon

    Printed 8 on the part. Easy to misread as B. Check that character with a loupe before you order anything.

    What it is
    Not recorded
    Maker
    Infineon
    Package
    Not recorded
    Pins
    Not recorded
    Source
    From the manufacturer's datasheet

    Is it dead?

    Diode range and ohms range, part lifted.

    Working, it reads

    Depends on what it is. The datasheet, or an identical part, says.

    Dead, it reads

    • Between two pins, the same reading both ways, near 0 V with a continuous beep: shorted.
    • Open between every pair of pins: failed open, or a part that reads open when working.
    On the board
    this is a first look only: the meter reads every path between those pins, and a short can be a neighbour. Lift one leg before you condemn it.
    Compare:
    If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor BBY58-02V, opens in a new tab
  • BBY58-03Wprinted 8Infineon

    Printed 8 on the part. Easy to misread as B. Check that character with a loupe before you order anything.

    What it is
    Not recorded
    Maker
    Infineon
    Package
    Not recorded
    Pins
    Not recorded
    Source
    From the manufacturer's datasheet

    Is it dead?

    Diode range and ohms range, part lifted.

    Working, it reads

    Depends on what it is. The datasheet, or an identical part, says.

    Dead, it reads

    • Between two pins, the same reading both ways, near 0 V with a continuous beep: shorted.
    • Open between every pair of pins: failed open, or a part that reads open when working.
    On the board
    this is a first look only: the meter reads every path between those pins, and a short can be a neighbour. Lift one leg before you condemn it.
    Compare:
    If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor BBY58-03W, opens in a new tab
  • PMEG3005AESFprinted 8Schottky diode, 2 pins, Nexperia

    Printed 8 on the part. Easy to misread as B. Check that character with a loupe before you order anything.

    What it is
    Schottky diode
    Maker
    Nexperia
    Package
    Not recorded
    Pins
    2
    Details
    30 V, 0.5 A low VF MEGA Schottky barrier rectifier
    Source
    From the manufacturer's datasheet

    Is it dead?

    Diode range, part lifted or one leg off the pad. Red probe on the anode.

    Working, it reads

    About 0.15 to 0.45 V anode to cathode, roughly half a silicon diode, and open the other way.

    Dead, it reads

    • The same reading both ways round, near 0 V with a continuous beep or the same middling value: shorted.
    • A reading the wrong way round as well: leaky.
    • Open both ways: failed open.
    On the board
    this is a first look only: the meter reads every path between those pins, and a short can be a neighbour. Lift one leg before you condemn it.
    Compare:
    If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
    Watch for:
    A large Schottky can read about 0.1 V forward and beep like a short, and leaks a little the wrong way when good, more when warm. It is shorted only if it reads the same both ways. Measure it cold, beside an identical cold one.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor PMEG3005AESF, opens in a new tab
298 more parts have codes that begin with B: 3 in X1SON, 295 with no package on record

Codes that begin with B

For a marking with its end worn or burnt off. Each one shows its full printed code.

  • TPD1E05U06DPYprinted BKX1SONESD protection diode, 2 pins, Texas Instruments

    Printed BK. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

    What it is
    ESD protection diode
    Maker
    Texas Instruments
    Package
    X1SON
    Pins
    2
    Details
    TPDxE05U06 1, 4, 6 Channel ESD Protection Device for Super-Speed (Up to 6 Gbps) Interface
    Source
    From the manufacturer's datasheet

    Is it dead?

    Diode range, from the protected line to ground, part lifted if you can.

    Working, it reads

    A one-way part reads about 0.6 to 0.8 V forward and open in reverse. A two-way part reads open both ways. Arrays with several lines read as the datasheet's diagram draws them.

    Dead, it reads

    • From the line to ground, the same reading both ways, near 0 V with a continuous beep: shorted.
    • A reading both ways on a one-way part: leaky.
    • A one-way part open both ways: failed open.
    On the board
    , a line reading shorted to ground can be this part or anything else on that line. Lift it: if the short goes with it, it has failed.
    Compare:
    The same part on the next line or connector pin is the healthy reading to compare with.
    Watch for:
    A two-way part reads open both ways when it is good, exactly like one that has failed open. The meter cannot tell them apart; an identical part on the next line can.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor TPD1E05U06DPY, opens in a new tab
  • TPD1E10B06DPYprinted B1X1SONESD protection diode, 2 pins, Texas Instruments

    Printed B1. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

    What it is
    ESD protection diode
    Maker
    Texas Instruments
    Package
    X1SON
    Pins
    2
    Details
    Single-Channel ESD Protection Diode
    Source
    From the manufacturer's datasheet

    Is it dead?

    Diode range, from the protected line to ground, part lifted if you can.

    Working, it reads

    A one-way part reads about 0.6 to 0.8 V forward and open in reverse. A two-way part reads open both ways. Arrays with several lines read as the datasheet's diagram draws them.

    Dead, it reads

    • From the line to ground, the same reading both ways, near 0 V with a continuous beep: shorted.
    • A reading both ways on a one-way part: leaky.
    • A one-way part open both ways: failed open.
    On the board
    , a line reading shorted to ground can be this part or anything else on that line. Lift it: if the short goes with it, it has failed.
    Compare:
    The same part on the next line or connector pin is the healthy reading to compare with.
    Watch for:
    A two-way part reads open both ways when it is good, exactly like one that has failed open. The meter cannot tell them apart; an identical part on the next line can.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor TPD1E10B06DPY, opens in a new tab
  • ESD401DPYprinted 8IX1SONESD protection diode, 2 pins, Texas Instruments

    Printed 8I. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

    What it is
    ESD protection diode
    Maker
    Texas Instruments
    Package
    X1SON
    Pins
    2
    Details
    1-Channel ESD Protection Diode With Robust IEC ESD Performance
    Source
    From the manufacturer's datasheet

    Is it dead?

    Diode range, from the protected line to ground, part lifted if you can.

    Working, it reads

    A one-way part reads about 0.6 to 0.8 V forward and open in reverse. A two-way part reads open both ways. Arrays with several lines read as the datasheet's diagram draws them.

    Dead, it reads

    • From the line to ground, the same reading both ways, near 0 V with a continuous beep: shorted.
    • A reading both ways on a one-way part: leaky.
    • A one-way part open both ways: failed open.
    On the board
    , a line reading shorted to ground can be this part or anything else on that line. Lift it: if the short goes with it, it has failed.
    Compare:
    The same part on the next line or connector pin is the healthy reading to compare with.
    Watch for:
    A two-way part reads open both ways when it is good, exactly like one that has failed open. The meter cannot tell them apart; an identical part on the next line can.

    A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

    Datasheetfor ESD401DPY, opens in a new tab
  • 22 more parts have no package on record. Nothing rules them out, so they stay.
    • 2SA2018printed BWPNP transistor, JSCJ

      Printed BW. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

      What it is
      PNP transistor
      Maker
      JSCJ
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Bipolar transistor, PNP
      Source
      From the manufacturer's datasheet

      Is it dead?

      Diode range, part lifted or its base leg off the pad.

      Working, it reads

      Black probe on the base reads about 0.6 to 0.75 V to the emitter and to the collector, and open the other way round. Collector to emitter reads open both ways.

      Dead, it reads

      • Collector to emitter the same both ways, near 0 V with a continuous beep: shorted. The commonest failure.
      • The base the same both ways to another pin, near 0 V or a middling value: a shorted junction.
      • Only one junction reads, or none: a junction has failed open. It then looks like a diode.
      • A reading the wrong way round, where it should be open: leaky.
      On the board
      this is a first look only: the meter reads every path between those pins, and a short can be a neighbour. Lift one leg before you condemn it.
      Compare:
      If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
      Watch for:
      A pair of diodes with a common pin reads just like a transistor, and some transistors carry a built-in diode or resistor. The datasheet says which.

      A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

      Datasheetfor 2SA2018, opens in a new tab
    • 2SC5585printed BXNPN transistor, JSCJ

      Printed BX. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

      What it is
      NPN transistor
      Maker
      JSCJ
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Bipolar transistor, NPN, 12 V, 0.5 A
      Source
      From the manufacturer's datasheet

      Is it dead?

      Diode range, part lifted or its base leg off the pad.

      Working, it reads

      Red probe on the base reads about 0.6 to 0.75 V to the emitter and to the collector, and open the other way round. Collector to emitter reads open both ways.

      Dead, it reads

      • Collector to emitter the same both ways, near 0 V with a continuous beep: shorted. The commonest failure.
      • The base the same both ways to another pin, near 0 V or a middling value: a shorted junction.
      • Only one junction reads, or none: a junction has failed open. It then looks like a diode.
      • A reading the wrong way round, where it should be open: leaky.
      On the board
      this is a first look only: the meter reads every path between those pins, and a short can be a neighbour. Lift one leg before you condemn it.
      Compare:
      If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
      Watch for:
      A pair of diodes with a common pin reads just like a transistor, and some transistors carry a built-in diode or resistor. The datasheet says which.

      A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

      Datasheetfor 2SC5585, opens in a new tab
    • 74AHCT1G08DRLprinted BESLogic gate, 5 pins, Texas Instruments

      Printed BES. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

      What it is
      Logic gate
      Maker
      Texas Instruments
      Package
      Not recorded
      Pins
      5
      Details
      Single 2-Input Positive-AND Gate
      Source
      From the manufacturer's datasheet

      Is it dead?

      Voltage with the board powered; ohms from each pin to ground with it off.

      Working, it reads

      Supply pin at its voltage and the output doing what the datasheet says. Readings between pins depend on the part.

      Dead, it reads

      • A pin near 0 Ω to ground or to the supply pin where an identical part does not read that: failed short.
      • Supply present, output stuck: failed, or its load has.
      On the board:
      A pin shorted to ground on the board can be anything on that net. Lift the pin to be sure.
      Compare:
      The surest reference is the same IC on a working board, measured pin by pin.
      Watch for:
      Its protection diodes can read like junctions between pins, even like a transistor. That proves nothing either way.

      A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

      Datasheetfor 74AHCT1G08DRL, opens in a new tab
    • AOB2140Lprinted B2140MOSFET, Alpha & Omega Semiconductor

      Printed B2140. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

      What it is
      MOSFET
      Maker
      Alpha & Omega Semiconductor
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Medium-voltage (40-400 V) MOSFET
      Source
      From the manufacturer's datasheet

      Is it dead?

      Diode range, part lifted. Test drain to source first, then short gate to source and test again.

      Working, it reads

      One way between drain and source reads about 0.4 to 0.9 V, the body diode, and the other way open. The gate reads open to both other pins.

      Dead, it reads

      • Drain to source the same both ways, near 0 V with a continuous beep, and still so after shorting gate to source: shorted. The classic failure.
      • The gate reads low to source or drain: gate shorted.
      • No body diode at all: failed open.
      On the board
      the gate usually has a resistor to the source, which reads as that resistor and is not a fault. Lift a leg to be sure.
      Compare:
      If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
      Watch for:
      The diode range can charge the gate enough to turn the part on, and then drain to source reads near 0 both ways on a good part. Short gate to source and test again before you condemn it.

      A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

      Datasheetfor AOB2140L, opens in a new tab
    • AOB2144Lprinted B2144MOSFET, Alpha & Omega Semiconductor

      Printed B2144. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

      What it is
      MOSFET
      Maker
      Alpha & Omega Semiconductor
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Medium-voltage (40-400 V) MOSFET
      Source
      From the manufacturer's datasheet

      Is it dead?

      Diode range, part lifted. Test drain to source first, then short gate to source and test again.

      Working, it reads

      One way between drain and source reads about 0.4 to 0.9 V, the body diode, and the other way open. The gate reads open to both other pins.

      Dead, it reads

      • Drain to source the same both ways, near 0 V with a continuous beep, and still so after shorting gate to source: shorted. The classic failure.
      • The gate reads low to source or drain: gate shorted.
      • No body diode at all: failed open.
      On the board
      the gate usually has a resistor to the source, which reads as that resistor and is not a fault. Lift a leg to be sure.
      Compare:
      If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
      Watch for:
      The diode range can charge the gate enough to turn the part on, and then drain to source reads near 0 both ways on a good part. Short gate to source and test again before you condemn it.

      A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

      Datasheetfor AOB2144L, opens in a new tab
    • AOB2146Lprinted B2146MOSFET, Alpha & Omega Semiconductor

      Printed B2146. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

      What it is
      MOSFET
      Maker
      Alpha & Omega Semiconductor
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Medium-voltage (40-400 V) MOSFET
      Source
      From the manufacturer's datasheet

      Is it dead?

      Diode range, part lifted. Test drain to source first, then short gate to source and test again.

      Working, it reads

      One way between drain and source reads about 0.4 to 0.9 V, the body diode, and the other way open. The gate reads open to both other pins.

      Dead, it reads

      • Drain to source the same both ways, near 0 V with a continuous beep, and still so after shorting gate to source: shorted. The classic failure.
      • The gate reads low to source or drain: gate shorted.
      • No body diode at all: failed open.
      On the board
      the gate usually has a resistor to the source, which reads as that resistor and is not a fault. Lift a leg to be sure.
      Compare:
      If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
      Watch for:
      The diode range can charge the gate enough to turn the part on, and then drain to source reads near 0 both ways on a good part. Short gate to source and test again before you condemn it.

      A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

      Datasheetfor AOB2146L, opens in a new tab
    • AOB2502Lprinted B2502MOSFET, Alpha & Omega Semiconductor

      Printed B2502. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

      What it is
      MOSFET
      Maker
      Alpha & Omega Semiconductor
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Medium-voltage (40-400 V) MOSFET
      Source
      From the manufacturer's datasheet

      Is it dead?

      Diode range, part lifted. Test drain to source first, then short gate to source and test again.

      Working, it reads

      One way between drain and source reads about 0.4 to 0.9 V, the body diode, and the other way open. The gate reads open to both other pins.

      Dead, it reads

      • Drain to source the same both ways, near 0 V with a continuous beep, and still so after shorting gate to source: shorted. The classic failure.
      • The gate reads low to source or drain: gate shorted.
      • No body diode at all: failed open.
      On the board
      the gate usually has a resistor to the source, which reads as that resistor and is not a fault. Lift a leg to be sure.
      Compare:
      If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
      Watch for:
      The diode range can charge the gate enough to turn the part on, and then drain to source reads near 0 both ways on a good part. Short gate to source and test again before you condemn it.

      A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

      Datasheetfor AOB2502L, opens in a new tab
    • AOB2904printed B2904MOSFET, Alpha & Omega Semiconductor

      Printed B2904. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

      What it is
      MOSFET
      Maker
      Alpha & Omega Semiconductor
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Medium-voltage (40-400 V) MOSFET
      Source
      From the manufacturer's datasheet

      Is it dead?

      Diode range, part lifted. Test drain to source first, then short gate to source and test again.

      Working, it reads

      One way between drain and source reads about 0.4 to 0.9 V, the body diode, and the other way open. The gate reads open to both other pins.

      Dead, it reads

      • Drain to source the same both ways, near 0 V with a continuous beep, and still so after shorting gate to source: shorted. The classic failure.
      • The gate reads low to source or drain: gate shorted.
      • No body diode at all: failed open.
      On the board
      the gate usually has a resistor to the source, which reads as that resistor and is not a fault. Lift a leg to be sure.
      Compare:
      If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
      Watch for:
      The diode range can charge the gate enough to turn the part on, and then drain to source reads near 0 both ways on a good part. Short gate to source and test again before you condemn it.

      A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

      Datasheetfor AOB2904, opens in a new tab
    • AOB66216Lprinted B66216MOSFET, Alpha & Omega Semiconductor

      Printed B66216. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

      What it is
      MOSFET
      Maker
      Alpha & Omega Semiconductor
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Medium-voltage (40-400 V) MOSFET
      Source
      From the manufacturer's datasheet

      Is it dead?

      Diode range, part lifted. Test drain to source first, then short gate to source and test again.

      Working, it reads

      One way between drain and source reads about 0.4 to 0.9 V, the body diode, and the other way open. The gate reads open to both other pins.

      Dead, it reads

      • Drain to source the same both ways, near 0 V with a continuous beep, and still so after shorting gate to source: shorted. The classic failure.
      • The gate reads low to source or drain: gate shorted.
      • No body diode at all: failed open.
      On the board
      the gate usually has a resistor to the source, which reads as that resistor and is not a fault. Lift a leg to be sure.
      Compare:
      If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
      Watch for:
      The diode range can charge the gate enough to turn the part on, and then drain to source reads near 0 both ways on a good part. Short gate to source and test again before you condemn it.

      A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

      Datasheetfor AOB66216L, opens in a new tab
    • AOB66613Lprinted B66613MOSFET, Alpha & Omega Semiconductor

      Printed B66613. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

      What it is
      MOSFET
      Maker
      Alpha & Omega Semiconductor
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Medium-voltage (40-400 V) MOSFET
      Source
      From the manufacturer's datasheet

      Is it dead?

      Diode range, part lifted. Test drain to source first, then short gate to source and test again.

      Working, it reads

      One way between drain and source reads about 0.4 to 0.9 V, the body diode, and the other way open. The gate reads open to both other pins.

      Dead, it reads

      • Drain to source the same both ways, near 0 V with a continuous beep, and still so after shorting gate to source: shorted. The classic failure.
      • The gate reads low to source or drain: gate shorted.
      • No body diode at all: failed open.
      On the board
      the gate usually has a resistor to the source, which reads as that resistor and is not a fault. Lift a leg to be sure.
      Compare:
      If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
      Watch for:
      The diode range can charge the gate enough to turn the part on, and then drain to source reads near 0 both ways on a good part. Short gate to source and test again before you condemn it.

      A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

      Datasheetfor AOB66613L, opens in a new tab
    • AOB66616printed B66616MOSFET, Alpha & Omega Semiconductor

      Printed B66616. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

      What it is
      MOSFET
      Maker
      Alpha & Omega Semiconductor
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Medium-voltage (40-400 V) MOSFET
      Source
      From the manufacturer's datasheet

      Is it dead?

      Diode range, part lifted. Test drain to source first, then short gate to source and test again.

      Working, it reads

      One way between drain and source reads about 0.4 to 0.9 V, the body diode, and the other way open. The gate reads open to both other pins.

      Dead, it reads

      • Drain to source the same both ways, near 0 V with a continuous beep, and still so after shorting gate to source: shorted. The classic failure.
      • The gate reads low to source or drain: gate shorted.
      • No body diode at all: failed open.
      On the board
      the gate usually has a resistor to the source, which reads as that resistor and is not a fault. Lift a leg to be sure.
      Compare:
      If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
      Watch for:
      The diode range can charge the gate enough to turn the part on, and then drain to source reads near 0 both ways on a good part. Short gate to source and test again before you condemn it.

      A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

      Datasheetfor AOB66616, opens in a new tab
    • AOB66620Lprinted B66620MOSFET, Alpha & Omega Semiconductor

      Printed B66620. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

      What it is
      MOSFET
      Maker
      Alpha & Omega Semiconductor
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Medium-voltage (40-400 V) MOSFET
      Source
      From the manufacturer's datasheet

      Is it dead?

      Diode range, part lifted. Test drain to source first, then short gate to source and test again.

      Working, it reads

      One way between drain and source reads about 0.4 to 0.9 V, the body diode, and the other way open. The gate reads open to both other pins.

      Dead, it reads

      • Drain to source the same both ways, near 0 V with a continuous beep, and still so after shorting gate to source: shorted. The classic failure.
      • The gate reads low to source or drain: gate shorted.
      • No body diode at all: failed open.
      On the board
      the gate usually has a resistor to the source, which reads as that resistor and is not a fault. Lift a leg to be sure.
      Compare:
      If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
      Watch for:
      The diode range can charge the gate enough to turn the part on, and then drain to source reads near 0 both ways on a good part. Short gate to source and test again before you condemn it.

      A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

      Datasheetfor AOB66620L, opens in a new tab
    • AOB66811Lprinted B66811MOSFET, Alpha & Omega Semiconductor

      Printed B66811. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

      What it is
      MOSFET
      Maker
      Alpha & Omega Semiconductor
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Medium-voltage (40-400 V) MOSFET
      Source
      From the manufacturer's datasheet

      Is it dead?

      Diode range, part lifted. Test drain to source first, then short gate to source and test again.

      Working, it reads

      One way between drain and source reads about 0.4 to 0.9 V, the body diode, and the other way open. The gate reads open to both other pins.

      Dead, it reads

      • Drain to source the same both ways, near 0 V with a continuous beep, and still so after shorting gate to source: shorted. The classic failure.
      • The gate reads low to source or drain: gate shorted.
      • No body diode at all: failed open.
      On the board
      the gate usually has a resistor to the source, which reads as that resistor and is not a fault. Lift a leg to be sure.
      Compare:
      If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
      Watch for:
      The diode range can charge the gate enough to turn the part on, and then drain to source reads near 0 both ways on a good part. Short gate to source and test again before you condemn it.

      A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

      Datasheetfor AOB66811L, opens in a new tab
    • AOB66916Lprinted B66916MOSFET, Alpha & Omega Semiconductor

      Printed B66916. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

      What it is
      MOSFET
      Maker
      Alpha & Omega Semiconductor
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Medium-voltage (40-400 V) MOSFET
      Source
      From the manufacturer's datasheet

      Is it dead?

      Diode range, part lifted. Test drain to source first, then short gate to source and test again.

      Working, it reads

      One way between drain and source reads about 0.4 to 0.9 V, the body diode, and the other way open. The gate reads open to both other pins.

      Dead, it reads

      • Drain to source the same both ways, near 0 V with a continuous beep, and still so after shorting gate to source: shorted. The classic failure.
      • The gate reads low to source or drain: gate shorted.
      • No body diode at all: failed open.
      On the board
      the gate usually has a resistor to the source, which reads as that resistor and is not a fault. Lift a leg to be sure.
      Compare:
      If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
      Watch for:
      The diode range can charge the gate enough to turn the part on, and then drain to source reads near 0 both ways on a good part. Short gate to source and test again before you condemn it.

      A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

      Datasheetfor AOB66916L, opens in a new tab
    • AOB66919Lprinted B66919MOSFET, Alpha & Omega Semiconductor

      Printed B66919. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

      What it is
      MOSFET
      Maker
      Alpha & Omega Semiconductor
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Medium-voltage (40-400 V) MOSFET
      Source
      From the manufacturer's datasheet

      Is it dead?

      Diode range, part lifted. Test drain to source first, then short gate to source and test again.

      Working, it reads

      One way between drain and source reads about 0.4 to 0.9 V, the body diode, and the other way open. The gate reads open to both other pins.

      Dead, it reads

      • Drain to source the same both ways, near 0 V with a continuous beep, and still so after shorting gate to source: shorted. The classic failure.
      • The gate reads low to source or drain: gate shorted.
      • No body diode at all: failed open.
      On the board
      the gate usually has a resistor to the source, which reads as that resistor and is not a fault. Lift a leg to be sure.
      Compare:
      If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
      Watch for:
      The diode range can charge the gate enough to turn the part on, and then drain to source reads near 0 both ways on a good part. Short gate to source and test again before you condemn it.

      A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

      Datasheetfor AOB66919L, opens in a new tab
    • AOB66920Lprinted B66920MOSFET, Alpha & Omega Semiconductor

      Printed B66920. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

      What it is
      MOSFET
      Maker
      Alpha & Omega Semiconductor
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Medium-voltage (40-400 V) MOSFET
      Source
      From the manufacturer's datasheet

      Is it dead?

      Diode range, part lifted. Test drain to source first, then short gate to source and test again.

      Working, it reads

      One way between drain and source reads about 0.4 to 0.9 V, the body diode, and the other way open. The gate reads open to both other pins.

      Dead, it reads

      • Drain to source the same both ways, near 0 V with a continuous beep, and still so after shorting gate to source: shorted. The classic failure.
      • The gate reads low to source or drain: gate shorted.
      • No body diode at all: failed open.
      On the board
      the gate usually has a resistor to the source, which reads as that resistor and is not a fault. Lift a leg to be sure.
      Compare:
      If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
      Watch for:
      The diode range can charge the gate enough to turn the part on, and then drain to source reads near 0 both ways on a good part. Short gate to source and test again before you condemn it.

      A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

      Datasheetfor AOB66920L, opens in a new tab
    • AOZ1268AQIprinted BZA0DC-DC converter, Alpha & Omega Semiconductor

      Printed BZA0. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

      What it is
      DC-DC converter
      Maker
      Alpha & Omega Semiconductor
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Synchronous buck regulator
      Source
      From the manufacturer's datasheet

      Is it dead?

      Voltage with the board powered; ohms from each pin to ground with it off.

      Working, it reads

      Supply pin at its voltage and the output doing what the datasheet says. Readings between pins depend on the part.

      Dead, it reads

      • A pin near 0 Ω to ground or to the supply pin where an identical part does not read that: failed short.
      • Supply present, output stuck: failed, or its load has.
      On the board:
      A pin shorted to ground on the board can be anything on that net. Lift the pin to be sure.
      Compare:
      The surest reference is the same IC on a working board, measured pin by pin.
      Watch for:
      Its protection diodes can read like junctions between pins, even like a transistor. That proves nothing either way.

      A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

      Datasheetfor AOZ1268AQI, opens in a new tab
    • AOZ1282CI-1printed BNDC-DC converter, Alpha & Omega Semiconductor

      Printed BN. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

      What it is
      DC-DC converter
      Maker
      Alpha & Omega Semiconductor
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Synchronous buck regulator
      Source
      From the manufacturer's datasheet

      Is it dead?

      Voltage with the board powered; ohms from each pin to ground with it off.

      Working, it reads

      Supply pin at its voltage and the output doing what the datasheet says. Readings between pins depend on the part.

      Dead, it reads

      • A pin near 0 Ω to ground or to the supply pin where an identical part does not read that: failed short.
      • Supply present, output stuck: failed, or its load has.
      On the board:
      A pin shorted to ground on the board can be anything on that net. Lift the pin to be sure.
      Compare:
      The surest reference is the same IC on a working board, measured pin by pin.
      Watch for:
      Its protection diodes can read like junctions between pins, even like a transistor. That proves nothing either way.

      A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

      Datasheetfor AOZ1282CI-1, opens in a new tab
    • AOZ1282CI-2printed BNDC-DC converter, Alpha & Omega Semiconductor

      Printed BN. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

      What it is
      DC-DC converter
      Maker
      Alpha & Omega Semiconductor
      Package
      Not recorded
      Pins
      Not recorded
      Details
      Synchronous buck regulator
      Source
      From the manufacturer's datasheet

      Is it dead?

      Voltage with the board powered; ohms from each pin to ground with it off.

      Working, it reads

      Supply pin at its voltage and the output doing what the datasheet says. Readings between pins depend on the part.

      Dead, it reads

      • A pin near 0 Ω to ground or to the supply pin where an identical part does not read that: failed short.
      • Supply present, output stuck: failed, or its load has.
      On the board:
      A pin shorted to ground on the board can be anything on that net. Lift the pin to be sure.
      Compare:
      The surest reference is the same IC on a working board, measured pin by pin.
      Watch for:
      Its protection diodes can read like junctions between pins, even like a transistor. That proves nothing either way.

      A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

      Datasheetfor AOZ1282CI-2, opens in a new tab
    • AOZ1327DI-01printed BC01Load switch, Alpha & Omega Semiconductor

      Printed BC01. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

      What it is
      Load switch
      Maker
      Alpha & Omega Semiconductor
      Package
      Not recorded
      Pins
      Not recorded
      Details
      USB Type-C protection switch
      Source
      From the manufacturer's datasheet

      Is it dead?

      Voltage, board powered, black probe on ground.

      Working, it reads

      Switched on, the output pin sits at the input voltage. Switched off, it sits near 0 V.

      Dead, it reads

      • Output at the input voltage while switched off: the pass element has shorted.
      • Input present and switched on, no output: failed open, or shut down into a shorted load. Power off and measure output to ground.
      On the board:
      An output near 0 Ω to ground is usually the load. Lift the output pin to see which.
      Compare:
      If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
      Watch for:
      The pinout and whether the enable is active high or low differ between parts. The datasheet gives both.

      A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

      Datasheetfor AOZ1327DI-01, opens in a new tab
    • AOZ1327DI-02printed BC02Load switch, Alpha & Omega Semiconductor

      Printed BC02. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

      What it is
      Load switch
      Maker
      Alpha & Omega Semiconductor
      Package
      Not recorded
      Pins
      Not recorded
      Details
      USB Type-C protection switch
      Source
      From the manufacturer's datasheet

      Is it dead?

      Voltage, board powered, black probe on ground.

      Working, it reads

      Switched on, the output pin sits at the input voltage. Switched off, it sits near 0 V.

      Dead, it reads

      • Output at the input voltage while switched off: the pass element has shorted.
      • Input present and switched on, no output: failed open, or shut down into a shorted load. Power off and measure output to ground.
      On the board:
      An output near 0 Ω to ground is usually the load. Lift the output pin to see which.
      Compare:
      If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
      Watch for:
      The pinout and whether the enable is active high or low differ between parts. The datasheet gives both.

      A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

      Datasheetfor AOZ1327DI-02, opens in a new tab
    • AOZ1328DI-01printed BG01Load switch, Alpha & Omega Semiconductor

      Printed BG01. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.

      What it is
      Load switch
      Maker
      Alpha & Omega Semiconductor
      Package
      Not recorded
      Pins
      Not recorded
      Details
      USB Type-C protection switch
      Source
      From the manufacturer's datasheet

      Is it dead?

      Voltage, board powered, black probe on ground.

      Working, it reads

      Switched on, the output pin sits at the input voltage. Switched off, it sits near 0 V.

      Dead, it reads

      • Output at the input voltage while switched off: the pass element has shorted.
      • Input present and switched on, no output: failed open, or shut down into a shorted load. Power off and measure output to ground.
      On the board:
      An output near 0 Ω to ground is usually the load. Lift the output pin to see which.
      Compare:
      If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
      Watch for:
      The pinout and whether the enable is active high or low differ between parts. The datasheet gives both.

      A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.

      Datasheetfor AOZ1328DI-01, opens in a new tab

273 more parts are not listed here. Type more of the code to narrow the list.

One code, several parts

Marking codes are not unique. In the standard code book, 6H on a SOT-23 is an NPN transistor, a varicap, an N-channel JFET, two digital transistors, a 3.6 V voltage detector: six parts from five makers. So a search shows the parts we hold under that code and under codes easily misread as it, with only the columns that tell them apart.

6Hon a SOT-23, in the code book
  • NPN transistor
  • Varicap
  • N-channel JFET
  • Digital transistor ×2
  • 3.6 V voltage detector

When more than one is left

Tap Help me choose. Up to 4 quick answers: whether the part has failed, then what separates the parts left. Those get ranked with the reasoning and a test that settles it. That uses one identification: 2 a month are free without an account, and 3 with a free account.

When you cannot read it

Tap the camera in the field. We read the characters, keep the ones we are unsure of, and search every reading. A photo too soft to read is turned back on your phone first; if it is the only one you can get, you can still send it.