SMD code search: identify a part by its marking
2 parts are printed ZQI. 81 printed with a similar-looking code.
2 parts are printed ZQI
Not sure which one you have?
Answer up to 4 quick questions and these 2 parts are ranked, with a meter test that settles it. It works on a dead part too.
Zener diode, all SMA, 2 pins, all JieJie.
SMAZPC180SMA
- What it is
- Zener diode
- Maker
- JieJie
- Package
- SMA
- Pins
- 2
- Source
- Manufacturer 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
- 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.
SMAZPC180AUSMA
- What it is
- Zener diode
- Maker
- JieJie
- Package
- SMA
- Pins
- 2
- Source
- Manufacturer 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
- 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.
81 more parts are printed with a code easy to misread as ZQI
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.
ACGRB201-HFprinted 201SMBRectifier, 2 pins, ComchipRectifierSMB2 pinsComchip
Printed 201 on the part. Easy to misread as ZQI. Check that character with a loupe before you order anything.
- What it is
- Rectifier
- Maker
- Comchip
- Package
- SMB
- Pins
- 2
- Details
- 50 V, 2 A rectifier
- Source
- Manufacturer 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.
ACURB201-HFprinted 201SMBRectifier, 2 pins, ComchipRectifierSMB2 pinsComchip
Printed 201 on the part. Easy to misread as ZQI. Check that character with a loupe before you order anything.
- What it is
- Rectifier
- Maker
- Comchip
- Package
- SMB
- Pins
- 2
- Details
- 50 V, 2 A rectifier
- Source
- Manufacturer 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.
AP3N028EYprinted Z01SOT-23-6N-channel MOSFET, 6 pins, Advanced Power ElectronicsN-channel MOSFETSOT-23-66 pinsAdvanced Power Electronics
Printed Z01 on the part. Easy to misread as ZQI. Check that character with a loupe before you order anything.
- What it is
- N-channel MOSFET
- Maker
- Advanced Power Electronics
- Package
- SOT-23-6
- Pins
- 6
- Details
- 30 V, 7 A N-channel MOSFET
- Source
- Manufacturer 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.
BZD27C120printed ZOISOD-123FZener diode, 2 pins, JieJieZener diodeSOD-123F2 pinsJieJie
Printed ZOI on the part. Easy to misread as ZQI. Check that character with a loupe before you order anything.
- What it is
- Zener diode
- Maker
- JieJie
- Package
- SOD-123F
- Pins
- 2
- Source
- Manufacturer 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
- 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.
BZD27C160printed ZOLSOD-123FZener diode, 2 pins, JieJieZener diodeSOD-123F2 pinsJieJie
Printed ZOL on the part. Easy to misread as ZQI. Check that character with a loupe before you order anything.
- What it is
- Zener diode
- Maker
- JieJie
- Package
- SOD-123F
- Pins
- 2
- Source
- Manufacturer 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
- 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.
CGRB201-HFprinted 201SMBRectifier, 2 pins, ComchipRectifierSMB2 pinsComchip
Printed 201 on the part. Easy to misread as ZQI. Check that character with a loupe before you order anything.
- What it is
- Rectifier
- Maker
- Comchip
- Package
- SMB
- Pins
- 2
- Details
- 50 V, 2 A rectifier
- Source
- Manufacturer 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.
S-5844A70CC-M5T1U3printed 2OISOT-23-5Temperature sensor, 5 pins, ABLICTemperature sensorSOT-23-55 pinsABLIC
Printed 2OI on the part. Easy to misread as ZQI. Check that character with a loupe before you order anything.
- What it is
- Temperature sensor
- Maker
- ABLIC
- Package
- SOT-23-5
- Pins
- 5
- Details
- TEMPERATURE SWITCH IC (THERMOSTAT IC)
- Source
- Manufacturer 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.
S-5844A70CD-M5T1U3printed 2QISOT-23-5Temperature sensor, 5 pins, ABLICTemperature sensorSOT-23-55 pinsABLIC
Printed 2QI on the part. Easy to misread as ZQI. Check that character with a loupe before you order anything.
- What it is
- Temperature sensor
- Maker
- ABLIC
- Package
- SOT-23-5
- Pins
- 5
- Details
- TEMPERATURE SWITCH IC (THERMOSTAT IC)
- Source
- Manufacturer 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.
SGM2078-1.8XN3Gprinted 2QLSOT-23LDO regulator, 3 pins, SG MicroLDO regulatorSOT-233 pinsSG Micro
Printed 2QL on the part. Easy to misread as ZQI. Check that character with a loupe before you order anything.
- What it is
- LDO regulator
- Maker
- SG Micro
- Package
- SOT-23
- Pins
- 3
- Details
- 1.8 V output, 300mA, 1.2V Logic, Low Power and Low Dropout RF Linear Regulator
- Source
- Manufacturer datasheet
Is it dead?
Voltage, board powered, black probe on ground. Then ohms with the power off.
Working, it reads
Input pin at the supply, output pin at its rated voltage, and the enable pin high if it has one.
Dead, it reads
- Output equal to the input: the pass element has shorted. Everything after it may have taken the full input.
- Input present, enable high, no output: failed open, or holding itself off into a shorted load. Power off and measure output to ground.
- Power off, input to output near 0 Ω: shorted.
- On the board:
- An output at 0 V is often a shorted load with the regulator in current limit. Lift the output pin: if the short stays on the board, the regulator may be fine.
- Compare:
- The same regulator on another rail or another board shows the right voltages and the right resistances.
- Watch for:
- Makers put input, output and ground on different pins in the same package, so take them from this part's datasheet. Diode or ohms readings between its pins say little; check it powered.
A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.
AC847BQprinted 2D1SOT-23NPN transistor, 3 pins, Diodes IncorporatedNPN transistorSOT-233 pinsDiodes Incorporated
Printed 2D1 on the part. Easy to misread as ZQI. Check that character with a loupe before you order anything.
- What it is
- NPN transistor
- Maker
- Diodes Incorporated
- Package
- SOT-23
- Pins
- 3
- Details
- NPN transistor: 50V, 100mA, 310mW, B=200..450, 300Mhz
- Source
- Published code list
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.
AP6213A-33DHNGAprinted 2QLSOT-23-5LDO regulator, 5 pins, Anwell SemiconductorLDO regulatorSOT-23-55 pinsAnwell Semiconductor
Printed 2QL on the part. Easy to misread as ZQI. Check that character with a loupe before you order anything.
- What it is
- LDO regulator
- Maker
- Anwell Semiconductor
- Package
- SOT-23-5
- Pins
- 5
- Details
- Linear voltage regulator IC: LDO, 3.3V±2%, 300mA. +CE, PDR, H-free
- Source
- Published code list
Is it dead?
Voltage, board powered, black probe on ground. Then ohms with the power off.
Working, it reads
Input pin at the supply, output pin at its rated voltage, and the enable pin high if it has one.
Dead, it reads
- Output equal to the input: the pass element has shorted. Everything after it may have taken the full input.
- Input present, enable high, no output: failed open, or holding itself off into a shorted load. Power off and measure output to ground.
- Power off, input to output near 0 Ω: shorted.
- On the board:
- An output at 0 V is often a shorted load with the regulator in current limit. Lift the output pin: if the short stays on the board, the regulator may be fine.
- Compare:
- The same regulator on another rail or another board shows the right voltages and the right resistances.
- Watch for:
- Makers put input, output and ground on different pins in the same package, so take them from this part's datasheet. Diode or ohms readings between its pins say little; check it powered.
A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.
AP6213A-33DHNGA1printed 2QLSOT-23-5LDO regulator, 5 pins, Anwell SemiconductorLDO regulatorSOT-23-55 pinsAnwell Semiconductor
Printed 2QL on the part. Easy to misread as ZQI. Check that character with a loupe before you order anything.
- What it is
- LDO regulator
- Maker
- Anwell Semiconductor
- Package
- SOT-23-5
- Pins
- 5
- Details
- Linear voltage regulator IC: LDO, 3.3V±1%, 300mA. +CE, PDR, H-free
- Source
- Published code list
Is it dead?
Voltage, board powered, black probe on ground. Then ohms with the power off.
Working, it reads
Input pin at the supply, output pin at its rated voltage, and the enable pin high if it has one.
Dead, it reads
- Output equal to the input: the pass element has shorted. Everything after it may have taken the full input.
- Input present, enable high, no output: failed open, or holding itself off into a shorted load. Power off and measure output to ground.
- Power off, input to output near 0 Ω: shorted.
- On the board:
- An output at 0 V is often a shorted load with the regulator in current limit. Lift the output pin: if the short stays on the board, the regulator may be fine.
- Compare:
- The same regulator on another rail or another board shows the right voltages and the right resistances.
- Watch for:
- Makers put input, output and ground on different pins in the same package, so take them from this part's datasheet. Diode or ohms readings between its pins say little; check it powered.
A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.
AP6213A-33DHNGPprinted 2QLSOT-353LDO regulator, 5 pins, Anwell SemiconductorLDO regulatorSOT-3535 pinsAnwell Semiconductor
Printed 2QL on the part. Easy to misread as ZQI. Check that character with a loupe before you order anything.
- What it is
- LDO regulator
- Maker
- Anwell Semiconductor
- Package
- SOT-353
- Pins
- 5
- Details
- Linear voltage regulator IC: LDO, 3.3V±2%, 300mA. +CE, PDR, H-free
- Source
- Published code list
Is it dead?
Voltage, board powered, black probe on ground. Then ohms with the power off.
Working, it reads
Input pin at the supply, output pin at its rated voltage, and the enable pin high if it has one.
Dead, it reads
- Output equal to the input: the pass element has shorted. Everything after it may have taken the full input.
- Input present, enable high, no output: failed open, or holding itself off into a shorted load. Power off and measure output to ground.
- Power off, input to output near 0 Ω: shorted.
- On the board:
- An output at 0 V is often a shorted load with the regulator in current limit. Lift the output pin: if the short stays on the board, the regulator may be fine.
- Compare:
- The same regulator on another rail or another board shows the right voltages and the right resistances.
- Watch for:
- Makers put input, output and ground on different pins in the same package, so take them from this part's datasheet. Diode or ohms readings between its pins say little; check it powered.
A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.
AP6213A-33DHNGP1printed 2QLSOT-353LDO regulator, 5 pins, Anwell SemiconductorLDO regulatorSOT-3535 pinsAnwell Semiconductor
Printed 2QL on the part. Easy to misread as ZQI. Check that character with a loupe before you order anything.
- What it is
- LDO regulator
- Maker
- Anwell Semiconductor
- Package
- SOT-353
- Pins
- 5
- Details
- Linear voltage regulator IC: LDO, 3.3V±1%, 300mA. +CE, PDR, H-free
- Source
- Published code list
Is it dead?
Voltage, board powered, black probe on ground. Then ohms with the power off.
Working, it reads
Input pin at the supply, output pin at its rated voltage, and the enable pin high if it has one.
Dead, it reads
- Output equal to the input: the pass element has shorted. Everything after it may have taken the full input.
- Input present, enable high, no output: failed open, or holding itself off into a shorted load. Power off and measure output to ground.
- Power off, input to output near 0 Ω: shorted.
- On the board:
- An output at 0 V is often a shorted load with the regulator in current limit. Lift the output pin: if the short stays on the board, the regulator may be fine.
- Compare:
- The same regulator on another rail or another board shows the right voltages and the right resistances.
- Watch for:
- Makers put input, output and ground on different pins in the same package, so take them from this part's datasheet. Diode or ohms readings between its pins say little; check it powered.
A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.
AP6213A-33DHNPAprinted 2QLSOT-23-5LDO regulator, 5 pins, Anwell SemiconductorLDO regulatorSOT-23-55 pinsAnwell Semiconductor
Printed 2QL on the part. Easy to misread as ZQI. Check that character with a loupe before you order anything.
- What it is
- LDO regulator
- Maker
- Anwell Semiconductor
- Package
- SOT-23-5
- Pins
- 5
- Details
- Linear voltage regulator IC: LDO, 3.3V±2%, 300mA. +CE, PDR
- Source
- Published code list
Is it dead?
Voltage, board powered, black probe on ground. Then ohms with the power off.
Working, it reads
Input pin at the supply, output pin at its rated voltage, and the enable pin high if it has one.
Dead, it reads
- Output equal to the input: the pass element has shorted. Everything after it may have taken the full input.
- Input present, enable high, no output: failed open, or holding itself off into a shorted load. Power off and measure output to ground.
- Power off, input to output near 0 Ω: shorted.
- On the board:
- An output at 0 V is often a shorted load with the regulator in current limit. Lift the output pin: if the short stays on the board, the regulator may be fine.
- Compare:
- The same regulator on another rail or another board shows the right voltages and the right resistances.
- Watch for:
- Makers put input, output and ground on different pins in the same package, so take them from this part's datasheet. Diode or ohms readings between its pins say little; check it powered.
A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.
AP6213A-33DHNPA1printed 2QLSOT-23-5LDO regulator, 5 pins, Anwell SemiconductorLDO regulatorSOT-23-55 pinsAnwell Semiconductor
Printed 2QL on the part. Easy to misread as ZQI. Check that character with a loupe before you order anything.
- What it is
- LDO regulator
- Maker
- Anwell Semiconductor
- Package
- SOT-23-5
- Pins
- 5
- Details
- Linear voltage regulator IC: LDO, 3.3V±1%, 300mA. +CE, PDR
- Source
- Published code list
Is it dead?
Voltage, board powered, black probe on ground. Then ohms with the power off.
Working, it reads
Input pin at the supply, output pin at its rated voltage, and the enable pin high if it has one.
Dead, it reads
- Output equal to the input: the pass element has shorted. Everything after it may have taken the full input.
- Input present, enable high, no output: failed open, or holding itself off into a shorted load. Power off and measure output to ground.
- Power off, input to output near 0 Ω: shorted.
- On the board:
- An output at 0 V is often a shorted load with the regulator in current limit. Lift the output pin: if the short stays on the board, the regulator may be fine.
- Compare:
- The same regulator on another rail or another board shows the right voltages and the right resistances.
- Watch for:
- Makers put input, output and ground on different pins in the same package, so take them from this part's datasheet. Diode or ohms readings between its pins say little; check it powered.
A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.
AP6213A-33DHNPPprinted 2QLSOT-353LDO regulator, 5 pins, Anwell SemiconductorLDO regulatorSOT-3535 pinsAnwell Semiconductor
Printed 2QL on the part. Easy to misread as ZQI. Check that character with a loupe before you order anything.
- What it is
- LDO regulator
- Maker
- Anwell Semiconductor
- Package
- SOT-353
- Pins
- 5
- Details
- Linear voltage regulator IC: LDO, 3.3V±2%, 300mA. +CE, PDR
- Source
- Published code list
Is it dead?
Voltage, board powered, black probe on ground. Then ohms with the power off.
Working, it reads
Input pin at the supply, output pin at its rated voltage, and the enable pin high if it has one.
Dead, it reads
- Output equal to the input: the pass element has shorted. Everything after it may have taken the full input.
- Input present, enable high, no output: failed open, or holding itself off into a shorted load. Power off and measure output to ground.
- Power off, input to output near 0 Ω: shorted.
- On the board:
- An output at 0 V is often a shorted load with the regulator in current limit. Lift the output pin: if the short stays on the board, the regulator may be fine.
- Compare:
- The same regulator on another rail or another board shows the right voltages and the right resistances.
- Watch for:
- Makers put input, output and ground on different pins in the same package, so take them from this part's datasheet. Diode or ohms readings between its pins say little; check it powered.
A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.
AP6213A-33DHNPP1printed 2QLSOT-353LDO regulator, 5 pins, Anwell SemiconductorLDO regulatorSOT-3535 pinsAnwell Semiconductor
Printed 2QL on the part. Easy to misread as ZQI. Check that character with a loupe before you order anything.
- What it is
- LDO regulator
- Maker
- Anwell Semiconductor
- Package
- SOT-353
- Pins
- 5
- Details
- Linear voltage regulator IC: LDO, 3.3V±1%, 300mA. +CE, PDR
- Source
- Published code list
Is it dead?
Voltage, board powered, black probe on ground. Then ohms with the power off.
Working, it reads
Input pin at the supply, output pin at its rated voltage, and the enable pin high if it has one.
Dead, it reads
- Output equal to the input: the pass element has shorted. Everything after it may have taken the full input.
- Input present, enable high, no output: failed open, or holding itself off into a shorted load. Power off and measure output to ground.
- Power off, input to output near 0 Ω: shorted.
- On the board:
- An output at 0 V is often a shorted load with the regulator in current limit. Lift the output pin: if the short stays on the board, the regulator may be fine.
- Compare:
- The same regulator on another rail or another board shows the right voltages and the right resistances.
- Watch for:
- Makers put input, output and ground on different pins in the same package, so take them from this part's datasheet. Diode or ohms readings between its pins say little; check it powered.
A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.
IXD3235F3LCER-Gprinted 2DLUSP-6CDC-DC converter, 6 pins, IXYSDC-DC converterUSP-6C6 pinsIXYS
Printed 2DL on the part. Easy to misread as ZQI. Check that character with a loupe before you order anything.
- What it is
- DC-DC converter
- Maker
- IXYS
- Package
- USP-6C
- Pins
- 6
- Details
- DC/DC voltage converter IC: PWM, st-dwn, 3.85V±2%, 600mA, 1.2MHz, Vin>1.8V, HSST, CL
- Source
- Published code list
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.
IXD3235F31CER-Gprinted 2D1USP-6CDC-DC converter, 6 pins, IXYSDC-DC converterUSP-6C6 pinsIXYS
Printed 2D1 on the part. Easy to misread as ZQI. Check that character with a loupe before you order anything.
- What it is
- DC-DC converter
- Maker
- IXYS
- Package
- USP-6C
- Pins
- 6
- Details
- DC/DC voltage converter IC: PWM, st-dwn, 3.1V±2%, 600mA, 1.2MHz, Vin>1.8V, HSST, CL
- Source
- Published code list
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.
IXD3235F31CMR-Gprinted 2D1SOT-23-5DC-DC converter, 5 pins, IXYSDC-DC converterSOT-23-55 pinsIXYS
Printed 2D1 on the part. Easy to misread as ZQI. Check that character with a loupe before you order anything.
- What it is
- DC-DC converter
- Maker
- IXYS
- Package
- SOT-23-5
- Pins
- 5
- Details
- DC/DC voltage converter IC: PWM, st-dwn, 3.1V±2%, 600mA, 1.2MHz, Vin>1.8V, HSST, CL
- Source
- Published code list
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.
MAZ3200-Lprinted 20LSOT-233 pins, PanNot recordedSOT-233 pinsPan
Printed 20L on the part. Easy to misread as ZQI. Check that character with a loupe before you order anything.
- What it is
- Not recorded
- Maker
- Pan
- Package
- SOT-23
- Pins
- 3
- Details
- Z-diode: 18.8..21.2V, If=100mA, Zzt=55Ω, 200mW
- Source
- Published code list
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.
26 more parts have no package on record
KDZ20WVprinted ZD1Zener diode, KECZener diodeNot recordedNot recordedKEC
Printed ZD1 on the part. Easy to misread as ZQI. Check that character with a loupe before you order anything.
- What it is
- Zener diode
- Maker
- KEC
- Package
- Not recorded
- Pins
- Not recorded
- Source
- Manufacturer 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
- 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.
S-5844A70CC-A4T2U3printed 2OITemperature sensor, ABLICTemperature sensorNot recordedNot recordedABLIC
Printed 2OI on the part. Easy to misread as ZQI. Check that character with a loupe before you order anything.
- What it is
- Temperature sensor
- Maker
- ABLIC
- Package
- Not recorded
- Pins
- Not recorded
- Details
- TEMPERATURE SWITCH IC (THERMOSTAT IC)
- Source
- Manufacturer 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.
S-5844A70CC-I4T1U3printed 2OITemperature sensor, ABLICTemperature sensorNot recordedNot recordedABLIC
Printed 2OI on the part. Easy to misread as ZQI. Check that character with a loupe before you order anything.
- What it is
- Temperature sensor
- Maker
- ABLIC
- Package
- Not recorded
- Pins
- Not recorded
- Details
- TEMPERATURE SWITCH IC (THERMOSTAT IC)
- Source
- Manufacturer 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.
S-5844A70CD-A4T2U3printed 2QITemperature sensor, ABLICTemperature sensorNot recordedNot recordedABLIC
Printed 2QI on the part. Easy to misread as ZQI. Check that character with a loupe before you order anything.
- What it is
- Temperature sensor
- Maker
- ABLIC
- Package
- Not recorded
- Pins
- Not recorded
- Details
- TEMPERATURE SWITCH IC (THERMOSTAT IC)
- Source
- Manufacturer 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.
S-5844A70CD-I4T1U3printed 2QITemperature sensor, ABLICTemperature sensorNot recordedNot recordedABLIC
Printed 2QI on the part. Easy to misread as ZQI. Check that character with a loupe before you order anything.
- What it is
- Temperature sensor
- Maker
- ABLIC
- Package
- Not recorded
- Pins
- Not recorded
- Details
- TEMPERATURE SWITCH IC (THERMOSTAT IC)
- Source
- Manufacturer 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.
SGM2228-2.5XTDI6Gprinted 2DILDO regulator, 6 pins, SG MicroLDO regulatorNot recorded6 pinsSG Micro
Printed 2DI on the part. Easy to misread as ZQI. Check that character with a loupe before you order anything.
- What it is
- LDO regulator
- Maker
- SG Micro
- Package
- Not recorded
- Pins
- 6
- Details
- 2.5 V output, 20V, 500mA, Low Noise, Low Dropout Linear Regulator
- Source
- Manufacturer datasheet
Is it dead?
Voltage, board powered, black probe on ground. Then ohms with the power off.
Working, it reads
Input pin at the supply, output pin at its rated voltage, and the enable pin high if it has one.
Dead, it reads
- Output equal to the input: the pass element has shorted. Everything after it may have taken the full input.
- Input present, enable high, no output: failed open, or holding itself off into a shorted load. Power off and measure output to ground.
- Power off, input to output near 0 Ω: shorted.
- On the board:
- An output at 0 V is often a shorted load with the regulator in current limit. Lift the output pin: if the short stays on the board, the regulator may be fine.
- Compare:
- The same regulator on another rail or another board shows the right voltages and the right resistances.
- Watch for:
- Makers put input, output and ground on different pins in the same package, so take them from this part's datasheet. Diode or ohms readings between its pins say little; check it powered.
A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.
SGM2228-3.3XTDI6Gprinted 2DLLDO regulator, 6 pins, SG MicroLDO regulatorNot recorded6 pinsSG Micro
Printed 2DL on the part. Easy to misread as ZQI. Check that character with a loupe before you order anything.
- What it is
- LDO regulator
- Maker
- SG Micro
- Package
- Not recorded
- Pins
- 6
- Details
- 3.3 V output, 20V, 500mA, Low Noise, Low Dropout Linear Regulator
- Source
- Manufacturer datasheet
Is it dead?
Voltage, board powered, black probe on ground. Then ohms with the power off.
Working, it reads
Input pin at the supply, output pin at its rated voltage, and the enable pin high if it has one.
Dead, it reads
- Output equal to the input: the pass element has shorted. Everything after it may have taken the full input.
- Input present, enable high, no output: failed open, or holding itself off into a shorted load. Power off and measure output to ground.
- Power off, input to output near 0 Ω: shorted.
- On the board:
- An output at 0 V is often a shorted load with the regulator in current limit. Lift the output pin: if the short stays on the board, the regulator may be fine.
- Compare:
- The same regulator on another rail or another board shows the right voltages and the right resistances.
- Watch for:
- Makers put input, output and ground on different pins in the same package, so take them from this part's datasheet. Diode or ohms readings between its pins say little; check it powered.
A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.
AP6213A-33DHNGSprinted 2QLLDO regulator, Anwell SemiconductorLDO regulatorNot recordedNot recordedAnwell Semiconductor
Printed 2QL on the part. Easy to misread as ZQI. Check that character with a loupe before you order anything.
- What it is
- LDO regulator
- Maker
- Anwell Semiconductor
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Linear voltage regulator IC: LDO, 3.3V±2%, 300mA, +CE, PDR, H-free
- Source
- Published code list
Is it dead?
Voltage, board powered, black probe on ground. Then ohms with the power off.
Working, it reads
Input pin at the supply, output pin at its rated voltage, and the enable pin high if it has one.
Dead, it reads
- Output equal to the input: the pass element has shorted. Everything after it may have taken the full input.
- Input present, enable high, no output: failed open, or holding itself off into a shorted load. Power off and measure output to ground.
- Power off, input to output near 0 Ω: shorted.
- On the board:
- An output at 0 V is often a shorted load with the regulator in current limit. Lift the output pin: if the short stays on the board, the regulator may be fine.
- Compare:
- The same regulator on another rail or another board shows the right voltages and the right resistances.
- Watch for:
- Makers put input, output and ground on different pins in the same package, so take them from this part's datasheet. Diode or ohms readings between its pins say little; check it powered.
A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.
AP6213A-33DHNGS1printed 2QLLDO regulator, Anwell SemiconductorLDO regulatorNot recordedNot recordedAnwell Semiconductor
Printed 2QL on the part. Easy to misread as ZQI. Check that character with a loupe before you order anything.
- What it is
- LDO regulator
- Maker
- Anwell Semiconductor
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Linear voltage regulator IC: LDO, 3.3V±1%, 300mA, +CE, PDR, H-free
- Source
- Published code list
Is it dead?
Voltage, board powered, black probe on ground. Then ohms with the power off.
Working, it reads
Input pin at the supply, output pin at its rated voltage, and the enable pin high if it has one.
Dead, it reads
- Output equal to the input: the pass element has shorted. Everything after it may have taken the full input.
- Input present, enable high, no output: failed open, or holding itself off into a shorted load. Power off and measure output to ground.
- Power off, input to output near 0 Ω: shorted.
- On the board:
- An output at 0 V is often a shorted load with the regulator in current limit. Lift the output pin: if the short stays on the board, the regulator may be fine.
- Compare:
- The same regulator on another rail or another board shows the right voltages and the right resistances.
- Watch for:
- Makers put input, output and ground on different pins in the same package, so take them from this part's datasheet. Diode or ohms readings between its pins say little; check it powered.
A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.
AP6213A-33DHNGUprinted 2QLLDO regulator, Anwell SemiconductorLDO regulatorNot recordedNot recordedAnwell Semiconductor
Printed 2QL on the part. Easy to misread as ZQI. Check that character with a loupe before you order anything.
- What it is
- LDO regulator
- Maker
- Anwell Semiconductor
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Linear voltage regulator IC: LDO, 3.3V±2%, 300mA. +CE, PDR, H-free
- Source
- Published code list
Is it dead?
Voltage, board powered, black probe on ground. Then ohms with the power off.
Working, it reads
Input pin at the supply, output pin at its rated voltage, and the enable pin high if it has one.
Dead, it reads
- Output equal to the input: the pass element has shorted. Everything after it may have taken the full input.
- Input present, enable high, no output: failed open, or holding itself off into a shorted load. Power off and measure output to ground.
- Power off, input to output near 0 Ω: shorted.
- On the board:
- An output at 0 V is often a shorted load with the regulator in current limit. Lift the output pin: if the short stays on the board, the regulator may be fine.
- Compare:
- The same regulator on another rail or another board shows the right voltages and the right resistances.
- Watch for:
- Makers put input, output and ground on different pins in the same package, so take them from this part's datasheet. Diode or ohms readings between its pins say little; check it powered.
A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.
AP6213A-33DHNGU1printed 2QLLDO regulator, Anwell SemiconductorLDO regulatorNot recordedNot recordedAnwell Semiconductor
Printed 2QL on the part. Easy to misread as ZQI. Check that character with a loupe before you order anything.
- What it is
- LDO regulator
- Maker
- Anwell Semiconductor
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Linear voltage regulator IC: LDO, 3.3V±1%, 300mA. +CE, PDR, H-free
- Source
- Published code list
Is it dead?
Voltage, board powered, black probe on ground. Then ohms with the power off.
Working, it reads
Input pin at the supply, output pin at its rated voltage, and the enable pin high if it has one.
Dead, it reads
- Output equal to the input: the pass element has shorted. Everything after it may have taken the full input.
- Input present, enable high, no output: failed open, or holding itself off into a shorted load. Power off and measure output to ground.
- Power off, input to output near 0 Ω: shorted.
- On the board:
- An output at 0 V is often a shorted load with the regulator in current limit. Lift the output pin: if the short stays on the board, the regulator may be fine.
- Compare:
- The same regulator on another rail or another board shows the right voltages and the right resistances.
- Watch for:
- Makers put input, output and ground on different pins in the same package, so take them from this part's datasheet. Diode or ohms readings between its pins say little; check it powered.
A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.
AP6213A-33DHNGWprinted 2QLLDO regulator, Anwell SemiconductorLDO regulatorNot recordedNot recordedAnwell Semiconductor
Printed 2QL on the part. Easy to misread as ZQI. Check that character with a loupe before you order anything.
- What it is
- LDO regulator
- Maker
- Anwell Semiconductor
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Linear voltage regulator IC: LDO, 3.3V±2%, 300mA, +CE, PDR, H-free
- Source
- Published code list
Is it dead?
Voltage, board powered, black probe on ground. Then ohms with the power off.
Working, it reads
Input pin at the supply, output pin at its rated voltage, and the enable pin high if it has one.
Dead, it reads
- Output equal to the input: the pass element has shorted. Everything after it may have taken the full input.
- Input present, enable high, no output: failed open, or holding itself off into a shorted load. Power off and measure output to ground.
- Power off, input to output near 0 Ω: shorted.
- On the board:
- An output at 0 V is often a shorted load with the regulator in current limit. Lift the output pin: if the short stays on the board, the regulator may be fine.
- Compare:
- The same regulator on another rail or another board shows the right voltages and the right resistances.
- Watch for:
- Makers put input, output and ground on different pins in the same package, so take them from this part's datasheet. Diode or ohms readings between its pins say little; check it powered.
A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.
AP6213A-33DHNGW1printed 2QLLDO regulator, Anwell SemiconductorLDO regulatorNot recordedNot recordedAnwell Semiconductor
Printed 2QL on the part. Easy to misread as ZQI. Check that character with a loupe before you order anything.
- What it is
- LDO regulator
- Maker
- Anwell Semiconductor
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Linear voltage regulator IC: LDO, 3.3V±1%, 300mA, +CE, PDR, H-free
- Source
- Published code list
Is it dead?
Voltage, board powered, black probe on ground. Then ohms with the power off.
Working, it reads
Input pin at the supply, output pin at its rated voltage, and the enable pin high if it has one.
Dead, it reads
- Output equal to the input: the pass element has shorted. Everything after it may have taken the full input.
- Input present, enable high, no output: failed open, or holding itself off into a shorted load. Power off and measure output to ground.
- Power off, input to output near 0 Ω: shorted.
- On the board:
- An output at 0 V is often a shorted load with the regulator in current limit. Lift the output pin: if the short stays on the board, the regulator may be fine.
- Compare:
- The same regulator on another rail or another board shows the right voltages and the right resistances.
- Watch for:
- Makers put input, output and ground on different pins in the same package, so take them from this part's datasheet. Diode or ohms readings between its pins say little; check it powered.
A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.
AP6213A-33DHNPSprinted 2QLLDO regulator, Anwell SemiconductorLDO regulatorNot recordedNot recordedAnwell Semiconductor
Printed 2QL on the part. Easy to misread as ZQI. Check that character with a loupe before you order anything.
- What it is
- LDO regulator
- Maker
- Anwell Semiconductor
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Linear voltage regulator IC: LDO, 3.3V±2%, 300mA, +CE, PDR
- Source
- Published code list
Is it dead?
Voltage, board powered, black probe on ground. Then ohms with the power off.
Working, it reads
Input pin at the supply, output pin at its rated voltage, and the enable pin high if it has one.
Dead, it reads
- Output equal to the input: the pass element has shorted. Everything after it may have taken the full input.
- Input present, enable high, no output: failed open, or holding itself off into a shorted load. Power off and measure output to ground.
- Power off, input to output near 0 Ω: shorted.
- On the board:
- An output at 0 V is often a shorted load with the regulator in current limit. Lift the output pin: if the short stays on the board, the regulator may be fine.
- Compare:
- The same regulator on another rail or another board shows the right voltages and the right resistances.
- Watch for:
- Makers put input, output and ground on different pins in the same package, so take them from this part's datasheet. Diode or ohms readings between its pins say little; check it powered.
A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.
AP6213A-33DHNPS1printed 2QLLDO regulator, Anwell SemiconductorLDO regulatorNot recordedNot recordedAnwell Semiconductor
Printed 2QL on the part. Easy to misread as ZQI. Check that character with a loupe before you order anything.
- What it is
- LDO regulator
- Maker
- Anwell Semiconductor
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Linear voltage regulator IC: LDO, 3.3V±1%, 300mA, +CE, PDR
- Source
- Published code list
Is it dead?
Voltage, board powered, black probe on ground. Then ohms with the power off.
Working, it reads
Input pin at the supply, output pin at its rated voltage, and the enable pin high if it has one.
Dead, it reads
- Output equal to the input: the pass element has shorted. Everything after it may have taken the full input.
- Input present, enable high, no output: failed open, or holding itself off into a shorted load. Power off and measure output to ground.
- Power off, input to output near 0 Ω: shorted.
- On the board:
- An output at 0 V is often a shorted load with the regulator in current limit. Lift the output pin: if the short stays on the board, the regulator may be fine.
- Compare:
- The same regulator on another rail or another board shows the right voltages and the right resistances.
- Watch for:
- Makers put input, output and ground on different pins in the same package, so take them from this part's datasheet. Diode or ohms readings between its pins say little; check it powered.
A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.
AP6213A-33DHNPUprinted 2QLLDO regulator, Anwell SemiconductorLDO regulatorNot recordedNot recordedAnwell Semiconductor
Printed 2QL on the part. Easy to misread as ZQI. Check that character with a loupe before you order anything.
- What it is
- LDO regulator
- Maker
- Anwell Semiconductor
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Linear voltage regulator IC: LDO, 3.3V±2%, 300mA. +CE, PDR
- Source
- Published code list
Is it dead?
Voltage, board powered, black probe on ground. Then ohms with the power off.
Working, it reads
Input pin at the supply, output pin at its rated voltage, and the enable pin high if it has one.
Dead, it reads
- Output equal to the input: the pass element has shorted. Everything after it may have taken the full input.
- Input present, enable high, no output: failed open, or holding itself off into a shorted load. Power off and measure output to ground.
- Power off, input to output near 0 Ω: shorted.
- On the board:
- An output at 0 V is often a shorted load with the regulator in current limit. Lift the output pin: if the short stays on the board, the regulator may be fine.
- Compare:
- The same regulator on another rail or another board shows the right voltages and the right resistances.
- Watch for:
- Makers put input, output and ground on different pins in the same package, so take them from this part's datasheet. Diode or ohms readings between its pins say little; check it powered.
A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.
AP6213A-33DHNPU1printed 2QLLDO regulator, Anwell SemiconductorLDO regulatorNot recordedNot recordedAnwell Semiconductor
Printed 2QL on the part. Easy to misread as ZQI. Check that character with a loupe before you order anything.
- What it is
- LDO regulator
- Maker
- Anwell Semiconductor
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Linear voltage regulator IC: LDO, 3.3V±1%, 300mA. +CE, PDR
- Source
- Published code list
Is it dead?
Voltage, board powered, black probe on ground. Then ohms with the power off.
Working, it reads
Input pin at the supply, output pin at its rated voltage, and the enable pin high if it has one.
Dead, it reads
- Output equal to the input: the pass element has shorted. Everything after it may have taken the full input.
- Input present, enable high, no output: failed open, or holding itself off into a shorted load. Power off and measure output to ground.
- Power off, input to output near 0 Ω: shorted.
- On the board:
- An output at 0 V is often a shorted load with the regulator in current limit. Lift the output pin: if the short stays on the board, the regulator may be fine.
- Compare:
- The same regulator on another rail or another board shows the right voltages and the right resistances.
- Watch for:
- Makers put input, output and ground on different pins in the same package, so take them from this part's datasheet. Diode or ohms readings between its pins say little; check it powered.
A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.
AP6213A-33DHNPWprinted 2QLLDO regulator, Anwell SemiconductorLDO regulatorNot recordedNot recordedAnwell Semiconductor
Printed 2QL on the part. Easy to misread as ZQI. Check that character with a loupe before you order anything.
- What it is
- LDO regulator
- Maker
- Anwell Semiconductor
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Linear voltage regulator IC: LDO, 3.3V±2%, 300mA, +CE, PDR
- Source
- Published code list
Is it dead?
Voltage, board powered, black probe on ground. Then ohms with the power off.
Working, it reads
Input pin at the supply, output pin at its rated voltage, and the enable pin high if it has one.
Dead, it reads
- Output equal to the input: the pass element has shorted. Everything after it may have taken the full input.
- Input present, enable high, no output: failed open, or holding itself off into a shorted load. Power off and measure output to ground.
- Power off, input to output near 0 Ω: shorted.
- On the board:
- An output at 0 V is often a shorted load with the regulator in current limit. Lift the output pin: if the short stays on the board, the regulator may be fine.
- Compare:
- The same regulator on another rail or another board shows the right voltages and the right resistances.
- Watch for:
- Makers put input, output and ground on different pins in the same package, so take them from this part's datasheet. Diode or ohms readings between its pins say little; check it powered.
A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.
AP6213A-33DHNPW1printed 2QLLDO regulator, Anwell SemiconductorLDO regulatorNot recordedNot recordedAnwell Semiconductor
Printed 2QL on the part. Easy to misread as ZQI. Check that character with a loupe before you order anything.
- What it is
- LDO regulator
- Maker
- Anwell Semiconductor
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Linear voltage regulator IC: LDO, 3.3V±1%, 300mA, +CE, PDR
- Source
- Published code list
Is it dead?
Voltage, board powered, black probe on ground. Then ohms with the power off.
Working, it reads
Input pin at the supply, output pin at its rated voltage, and the enable pin high if it has one.
Dead, it reads
- Output equal to the input: the pass element has shorted. Everything after it may have taken the full input.
- Input present, enable high, no output: failed open, or holding itself off into a shorted load. Power off and measure output to ground.
- Power off, input to output near 0 Ω: shorted.
- On the board:
- An output at 0 V is often a shorted load with the regulator in current limit. Lift the output pin: if the short stays on the board, the regulator may be fine.
- Compare:
- The same regulator on another rail or another board shows the right voltages and the right resistances.
- Watch for:
- Makers put input, output and ground on different pins in the same package, so take them from this part's datasheet. Diode or ohms readings between its pins say little; check it powered.
A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.
HZM20NB1printed 201Zener diode, RenesasZener diodeNot recordedNot recordedRenesas
Printed 201 on the part. Easy to misread as ZQI. Check that character with a loupe before you order anything.
- What it is
- Zener diode
- Maker
- Renesas
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Z-diode: 18.86..19.7V, 200mW
- Source
- Published code list
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
- 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.
HZU20L-1printed 201Zener diode, RenesasZener diodeNot recordedNot recordedRenesas
Printed 201 on the part. Easy to misread as ZQI. Check that character with a loupe before you order anything.
- What it is
- Zener diode
- Maker
- Renesas
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Z-diode: 18.8..19.7V, 150mW
- Source
- Published code list
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
- 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.
IXD3235F3LC0R-Gprinted 2DLDC-DC converter, IXYSDC-DC converterNot recordedNot recordedIXYS
Printed 2DL on the part. Easy to misread as ZQI. Check that character with a loupe before you order anything.
- What it is
- DC-DC converter
- Maker
- IXYS
- Package
- Not recorded
- Pins
- Not recorded
- Details
- DC/DC voltage converter IC: PWM, st-dwn, 3.85V±2%, 600mA, 1.2MHz, Vin>1.8V, HSST, CL
- Source
- Published code list
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.
IXD3235F3LC4R-Gprinted 2DLDC-DC converter, IXYSDC-DC converterNot recordedNot recordedIXYS
Printed 2DL on the part. Easy to misread as ZQI. Check that character with a loupe before you order anything.
- What it is
- DC-DC converter
- Maker
- IXYS
- Package
- Not recorded
- Pins
- Not recorded
- Details
- DC/DC voltage converter IC: PWM, st-dwn, 3.85V±2%, 600mA, 1.2MHz, Vin>1.8V, HSST, CL
- Source
- Published code list
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.
IXD3235F31C0R-Gprinted 2D1DC-DC converter, IXYSDC-DC converterNot recordedNot recordedIXYS
Printed 2D1 on the part. Easy to misread as ZQI. Check that character with a loupe before you order anything.
- What it is
- DC-DC converter
- Maker
- IXYS
- Package
- Not recorded
- Pins
- Not recorded
- Details
- DC/DC voltage converter IC: PWM, st-dwn, 3.1V±2%, 600mA, 1.2MHz, Vin>1.8V, HSST, CL
- Source
- Published code list
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.
IXD3235F31C4R-Gprinted 2D1DC-DC converter, IXYSDC-DC converterNot recordedNot recordedIXYS
Printed 2D1 on the part. Easy to misread as ZQI. Check that character with a loupe before you order anything.
- What it is
- DC-DC converter
- Maker
- IXYS
- Package
- Not recorded
- Pins
- Not recorded
- Details
- DC/DC voltage converter IC: PWM, st-dwn, 3.1V±2%, 600mA, 1.2MHz, Vin>1.8V, HSST, CL
- Source
- Published code list
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.
PD3Z284C6V8printed Z0LZener diode, Diodes IncorporatedZener diodeNot recordedNot recordedDiodes Incorporated
Printed Z0L on the part. Easy to misread as ZQI. Check that character with a loupe before you order anything.
- What it is
- Zener diode
- Maker
- Diodes Incorporated
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Z-diode: 6.8..7.2V, 5mA, Zzt=15, 500mW
- Source
- Published code list
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
- 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.
33 more parts are not listed here. Type more of the code to narrow the list.
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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 on WhatSMD (What SMD) shows the parts we hold under that code and under codes easily misread as it, with only the columns that tell them apart.
- 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.
Get the app
The same search on your phone, and a camera with a light, zoom and tap to focus for a marking you cannot read. Sign in with your email address to use the same account.
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