SMD marking

Bin SOD-523

Marking codes are not standardised, and the same code is reused by unrelated makers for unrelated parts. Below is every part in our tables printed with it, and any printed with a code that is easy to misread as it, from the manufacturers' own marking tables.

22 parts are printed B

Not sure which one you have?

Answer up to 4 quick questions and these 22 parts are ranked, with a meter test that settles it. It works on a dead part too.

RB520S-30SOD-523Schottky diode, 2 pins, JSCJSchottky diode2 pinsJSCJ
What it is
Schottky diode
Maker
JSCJ
Package
SOD-523
Pins
2
Details
Schottky diode, 30 V, 0.2 A
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:
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 RB520S-30, opens in a new tab
VBUS05M1-02VSOD-523ESD protection diode, 2 pins, VishayESD protection diode2 pinsVishay
What it is
ESD protection diode
Maker
Vishay
Package
SOD-523
Pins
2
Details
Low Capacitance Single Line ESD-Protection Diode in SOD-523
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:
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 VBUS05M1-02V, opens in a new tab
20 more parts have no package on record. Nothing rules them out, so they stay.
- AON1606MOSFET, Alpha & Omega SemiconductorMOSFETNot recordedAlpha & 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:
  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 SemiconductorMOSFETNot recordedAlpha & 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:
  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 SemiconductorESD protection diodeNot recordedAlpha & 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:
  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 SemiconductorESD protection diodeNot recordedAlpha & 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:
  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 SemiconductorESD protection diodeNot recordedAlpha & 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:
  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 SemiconductorESD protection diodeNot recordedAlpha & 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:
  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, InfineonSwitching diodeNot recordedInfineon
  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:
  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, InfineonSchottky diodeNot recordedInfineon
  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:
  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
- BB555-02VInfineonNot recordedNot recordedInfineon
  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:
  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, JSCJESD protection diodeNot recordedJSCJ
  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:
  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, InfineonESD protection diodeNot recordedInfineon
  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:
  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, JSCJESD protection diodeNot recordedJSCJ
  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:
  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, InfineonN-channel MOSFETNot recordedInfineon
  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:
  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, PanjitESD protection diodeNot recordedPanjit
  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:
  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, PanjitESD protection diodeNot recordedPanjit
  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:
  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 SemiconductorSchottky diodeNot recordedTaiwan 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:
  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 SemiconductorSchottky diodeNot recordedTaiwan 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:
  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
- TLV809EA24DPWVoltage supervisor, 5 pins, Texas InstrumentsVoltage supervisor5 pinsTexas Instruments
  What it is
  Voltage supervisor
  Maker
  Texas Instruments
  Package
  Not recorded
  Pins
  5
  Details
  Low Power 250-nA IQ and Small Size Supply Voltage Supervisors
  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 TLV809EA24DPW, opens in a new tab
- VCAN33A2-HT5ESD protection diode, VishayESD protection diodeNot recordedVishay
  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:
  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, VishayESD protection diodeNot recordedVishay
  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:
  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

7 more parts are printed with a code easy to misread as B

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.

AOZ8S503BDS-05printed 8ESD protection diode, Alpha & Omega SemiconductorESD protection diodeNot recordedAlpha & 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:
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 SemiconductorESD protection diodeNot recordedAlpha & 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:
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 SemiconductorESD protection diodeNot recordedAlpha & 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:
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 8InfineonNot recordedNot recordedInfineon
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:
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 8InfineonNot recordedNot recordedInfineon
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:
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, NexperiaSchottky diode2 pinsNexperia
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:
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
TLV803EA38DPWprinted 8Voltage supervisor, 5 pins, Texas InstrumentsVoltage supervisor5 pinsTexas Instruments
Printed 8 on the part. Easy to misread as B. Check that character with a loupe before you order anything.
What it is
Voltage supervisor
Maker
Texas Instruments
Package
Not recorded
Pins
5
Details
Low Power 250-nA IQ and Small Size Supply Voltage Supervisors
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 TLV803EA38DPW, opens in a new tab

21 more parts have codes that begin with B

Codes that begin with B

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

CESDB5V0D5printed B5SOD-523ESD protection diode, 2 pins, JSCJESD protection diode2 pinsJSCJ
Printed B5. 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
JSCJ
Package
SOD-523
Pins
2
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:
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 CESDB5V0D5, opens in a new tab
CESDBLC5V0D5printed BHSOD-523ESD protection diode, 2 pins, JSCJESD protection diode2 pinsJSCJ
Printed BH. 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
JSCJ
Package
SOD-523
Pins
2
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:
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 CESDBLC5V0D5, opens in a new tab
ESDB3V0D5printed B3SOD-523ESD protection diode, 2 pins, JSCJESD protection diode2 pinsJSCJ
Printed B3. 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
JSCJ
Package
SOD-523
Pins
2
Details
ESD protection diode, VRWM 3 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:
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 ESDB3V0D5, opens in a new tab
PEC3202ESprinted BASOD-523ESD protection diode, 2 pins, PanjitESD protection diode2 pinsPanjit
Printed BA. 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
Panjit
Package
SOD-523
Pins
2
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:
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 PEC3202ES, opens in a new tab
PEC3203ESprinted BBSOD-523ESD protection diode, 2 pins, PanjitESD protection diode2 pinsPanjit
Printed BB. 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
Panjit
Package
SOD-523
Pins
2
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:
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 PEC3203ES, opens in a new tab
PEC3205ESprinted BCSOD-523ESD protection diode, 2 pins, PanjitESD protection diode2 pinsPanjit
Printed BC. 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
Panjit
Package
SOD-523
Pins
2
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:
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 PEC3205ES, opens in a new tab
PMEG6002EBprinted B2SOD-523Schottky diode, 2 pins, NexperiaSchottky diode2 pinsNexperia
Printed B2. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
What it is
Schottky diode
Maker
Nexperia
Package
SOD-523
Pins
2
Details
60 V, 0.2 A very low VF 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:
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 PMEG6002EB, opens in a new tab
PZS1118BESprinted 8QSOD-523Zener diode, 2 pins, PanjitZener diode2 pinsPanjit
Printed 8Q. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
What it is
Zener diode
Maker
Panjit
Package
SOD-523
Pins
2
Source
From the manufacturer's datasheet
Is it dead?
Diode range for the forward check, part lifted, red probe on the anode. A bench supply for the Zener voltage.
Working, it reads
About 0.6 to 0.8 V forward and open in reverse on the diode range. Its Zener voltage shows only on a supply: feed it through a resistor that sets about 5 mA, cathode to positive, read quickly, and it should hold near its rated voltage.
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, forward too: failed open.
Holds well off its rated voltage on the supply test: drifted.
A soft knee, or a voltage that creeps on the supply test: leaky.
On the board:
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 meter's diode range stops at about 2 to 3 V, so almost every Zener reads open in reverse on it, good or bad; a 3 V meter may just show a 2.4 or 2.7 V part. Above about 3 V the meter cannot tell a Zener from a plain diode.
A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.
Datasheetfor PZS1118BES, opens in a new tab
13 more parts have no package on record. Nothing rules them out, so they stay.
- 2SA2018printed BWPNP transistor, JSCJPNP transistorNot recordedJSCJ
  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:
  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, JSCJNPN transistorNot recordedJSCJ
  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:
  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 InstrumentsLogic gate5 pinsTexas 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 SemiconductorMOSFETNot recordedAlpha & 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:
  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 SemiconductorMOSFETNot recordedAlpha & 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:
  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 SemiconductorMOSFETNot recordedAlpha & 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:
  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 SemiconductorMOSFETNot recordedAlpha & 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:
  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 SemiconductorMOSFETNot recordedAlpha & 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:
  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 SemiconductorMOSFETNot recordedAlpha & 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:
  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 SemiconductorMOSFETNot recordedAlpha & 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:
  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 SemiconductorMOSFETNot recordedAlpha & 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:
  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 SemiconductorMOSFETNot recordedAlpha & 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:
  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 SemiconductorMOSFETNot recordedAlpha & 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:
  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

Open this in the search to correct a character or try another package.

22 parts are printed B

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Printed with a code easy to misread

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Codes that begin with B

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