SMD code 1A
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.
13 parts are printed 1A
Not sure which one you have?
Answer up to 4 quick questions and these 13 parts are ranked, with a meter test that settles it. It works on a dead part too.
BC846ASOT-23NPN transistor, 3 pins, InfineonNPN transistorSOT-233 pinsInfineon
- What it is
- NPN transistor
- Maker
- Infineon
- Package
- SOT-23
- Pins
- 3
- Pinout
- 1 base
- 2 emitter
- 3 collector
- Details
- 65 V NPN small-signal transistor, gain group A
- Source
- From the manufacturer's datasheet
Is it dead? The meter test is below: NPN transistor.
BC846ATSOT-416NPN transistor, 3 pins, NexperiaNPN transistorSOT-4163 pinsNexperia
- What it is
- NPN transistor
- Maker
- Nexperia
- Package
- SOT-416
- Pins
- 3
- Pinout
- 1 base
- 2 emitter
- 3 collector
- Details
- 65 V, 100 mA NPN general-purpose transistor
- Source
- From the manufacturer's datasheet
Is it dead? The meter test is below: NPN transistor.
BC846AWSOT-323Transistor, 3 pins, DiotecTransistorSOT-3233 pinsDiotec
- What it is
- Transistor
- Maker
- Diotec
- Package
- SOT-323
- Pins
- 3
- Pinout
- 1 base
- 2 emitter
- 3 collector
- Details
- SMD General Purpose NPN Transistors
- Source
- From the manufacturer's datasheet
Is it dead? The meter test is below: Bipolar transistor.
MMBT3904SOT-23NPN transistor, 3 pins, InfineonNPN transistorSOT-233 pinsInfineon
- What it is
- NPN transistor
- Maker
- Infineon
- Package
- SOT-23
- Pins
- 3
- Details
- 40 V NPN small-signal transistor
- Source
- From the manufacturer's datasheet
Is it dead? The meter test is below: NPN transistor.
PJSOT03SOT-23ESD protection diode, 3 pins, PanjitESD protection diodeSOT-233 pinsPanjit
- What it is
- ESD protection diode
- Maker
- Panjit
- Package
- SOT-23
- Pins
- 3
- Source
- From the manufacturer's datasheet
Is it dead? The meter test is below: TVS or ESD protection diode.
PMBT3904SOT-23NPN transistor, 3 pins, NexperiaNPN transistorSOT-233 pinsNexperia
- What it is
- NPN transistor
- Maker
- Nexperia
- Package
- SOT-23
- Pins
- 3
- Pinout
- 1 base
- 2 emitter
- 3 collector
- Details
- 40 V, 200 mA NPN switching transistor
- Source
- From the manufacturer's datasheet
Is it dead? The meter test is below: NPN transistor.
PMST3904SOT-323NPN transistor, 3 pins, NexperiaNPN transistorSOT-3233 pinsNexperia
- What it is
- NPN transistor
- Maker
- Nexperia
- Package
- SOT-323
- Pins
- 3
- Details
- NPN switching transistor
- Source
- From the manufacturer's datasheet
Is it dead? The meter test is below: NPN transistor.
PS2405-D63SOT-883ESD protection diode, 3 pins, PanjitESD protection diodeSOT-8833 pinsPanjit
- What it is
- ESD protection diode
- Maker
- Panjit
- Package
- SOT-883
- Pins
- 3
- Source
- From the manufacturer's datasheet
Is it dead? The meter test is below: TVS or ESD protection diode.
PXT3904SOT-89NPN transistor, 3 pins, JSCJNPN transistorSOT-893 pinsJSCJ
- What it is
- NPN transistor
- Maker
- JSCJ
- Package
- SOT-89
- Pins
- 3
- Details
- Bipolar transistor, NPN, 40 V, 0.2 A
- Source
- From the manufacturer's datasheet
Is it dead? The meter test is below: NPN transistor.
SD101AWSSOD-323Schottky diode, 2 pins, VishaySchottky diodeSOD-3232 pinsVishay
- What it is
- Schottky diode
- Maker
- Vishay
- Package
- SOD-323
- Pins
- 2
- Details
- Schottky diode, 60 V
- Source
- From the manufacturer's datasheet
Is it dead? The meter test is below: Schottky diode.
TS431ACXSOT-23Voltage reference, 3 pins, Taiwan SemiconductorVoltage referenceSOT-233 pinsTaiwan Semiconductor
- What it is
- Voltage reference
- Maker
- Taiwan Semiconductor
- Package
- SOT-23
- Pins
- 3
- Source
- From the manufacturer's datasheet
Is it dead? The meter test is below: Integrated circuit.
2 more parts have no package on record
GMF05C-HSFESD protection diode, VishayESD protection diodeNot recordedNot recordedVishay
- What it is
- ESD protection diode
- Maker
- Vishay
- Package
- Not recorded
- Pins
- Not recorded
- Details
- 5-Line ESD Protection Diode Array in LLP75-6L
- Source
- From the manufacturer's datasheet
Is it dead? The meter test is below: TVS or ESD protection diode.
SMBT3904Transistor, InfineonTransistorNot recordedNot recordedInfineon
- What it is
- Transistor
- Maker
- Infineon
- Package
- Not recorded
- Pins
- Not recorded
- Source
- From the manufacturer's datasheet
Is it dead? The meter test is below: Bipolar transistor.
Is it dead? One meter test per kind
Parts of the same kind are tested the same way, so each test is here once. Each part above points to its own.
NPN transistor
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.
Bipolar transistor
Diode range, part lifted or its base leg off the pad.
Working, it reads
From the base, one probe colour 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.
TVS or ESD protection diode
Diode range, from the protected line to ground, part lifted if you can.
Working, it reads
A one-way part reads about 0.6 to 0.8 V forward and open in reverse. A two-way part reads open both ways. Arrays with several lines read as the datasheet's diagram draws them.
Dead, it reads
- From the line to ground, the same reading both ways, near 0 V with a continuous beep: shorted.
- A reading both ways on a one-way part: leaky.
- A one-way part open both ways: failed open.
- On the board
- , a line reading shorted to ground can be this part or anything else on that line. Lift it: if the short goes with it, it has failed.
- Compare:
- The same part on the next line or connector pin is the healthy reading to compare with.
- Watch for:
- A two-way part reads open both ways when it is good, exactly like one that has failed open. The meter cannot tell them apart; an identical part on the next line can.
A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.
Schottky diode
Diode range, part lifted or one leg off the pad. Red probe on the anode.
Working, it reads
About 0.15 to 0.45 V anode to cathode, roughly half a silicon diode, and open the other way.
Dead, it reads
- The same reading both ways round, near 0 V with a continuous beep or the same middling value: shorted.
- A reading the wrong way round as well: leaky.
- Open both ways: failed open.
- On the board
- this is a first look only: the meter reads every path between those pins, and a short can be a neighbour. Lift one leg before you condemn it.
- Compare:
- If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
- Watch for:
- A large Schottky can read about 0.1 V forward and beep like a short, and leaks a little the wrong way when good, more when warm. It is shorted only if it reads the same both ways. Measure it cold, beside an identical cold one.
A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.
Integrated circuit
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.
Printed with a code easy to misread as 1A
One character differs, and it is one that is easy to confuse under a lamp. Each code has a page of its own.
Codes that begin with 1A
For a marking with its end worn or burnt off. Each code has a page of its own.
Codes not listed here are printed on 3 more parts.
Open this in the search to correct a character or try another package.