SMD code 1B-
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 and published code lists.
128 parts are printed 1B-
Not sure which one you have?
Answer up to 4 quick questions and these 50 parts are ranked, with a meter test that settles it. It works on a dead part too.
SBC846BWSOT-323NPN transistor, 3 pins, onsemiNPN transistorSOT-3233 pinsonsemi
- What it is
- NPN transistor
- Maker
- onsemi
- Package
- SOT-323
- Pins
- 3
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: NPN transistor.
SD101BWSSOD-323Schottky diode, 2 pins, VishaySchottky diodeSOD-3232 pinsVishay
- What it is
- Schottky diode
- Maker
- Vishay
- Package
- SOD-323
- Pins
- 2
- Details
- 0.015A, 50V, Surface Mount Small Signal Schottky Diodes
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Schottky diode.
TBC846BSOT-23NPN transistor, 3 pins, Galaxy MicroelectronicsNPN transistorSOT-233 pinsGalaxy Microelectronics
- What it is
- NPN transistor
- Maker
- Galaxy Microelectronics
- Package
- SOT-23
- Pins
- 3
- Details
- 65V, 0.1A, General Purpose NPN Bipolar Transistor
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: NPN transistor.
TL431BL3TSOT-23Voltage reference, 3 pins, STMicroelectronicsVoltage referenceSOT-233 pinsSTMicroelectronics
- What it is
- Voltage reference
- Maker
- STMicroelectronics
- Package
- SOT-23
- Pins
- 3
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Integrated circuit.
TS431BCXSOT-23Voltage reference, 3 pins, Taiwan SemiconductorVoltage referenceSOT-233 pinsTaiwan Semiconductor
- What it is
- Voltage reference
- Maker
- Taiwan Semiconductor
- Package
- SOT-23
- Pins
- 3
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Integrated circuit.
WT846BSOT-233 pins, WayonNot recordedSOT-233 pinsWayon
- What it is
- Not recorded
- Maker
- Wayon
- Package
- SOT-23
- Pins
- 3
- Details
- Bipolar transistor
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Bipolar transistor.
2N2222SOT-233 pins, Texas InstrumentsNot recordedSOT-233 pinsTexas Instruments
- What it is
- Not recorded
- Maker
- Texas Instruments
- Package
- SOT-23
- Pins
- 3
- Details
- Si-npn: GP, 60V, 600mA, 330mW, B=100..300, >250MHz
- Source
- Published code list
Is it dead? The meter test is below: This part.
7UL1T125FUSOT-3535 pins, ToshibaNot recordedSOT-3535 pinsToshiba
- What it is
- Not recorded
- Maker
- Toshiba
- Package
- SOT-353
- Pins
- 5
- Details
- CMOS logic IC: Bus buffer gate with 3-state output
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
BC846B9SOT-233 pins, CdiNot recordedSOT-233 pinsCdi
- What it is
- Not recorded
- Maker
- Cdi
- Package
- SOT-23
- Pins
- 3
- Details
- Si-npn: GP, 80V, 100mA, 250mW, B=200..450, >100MHz
- Source
- Published code list
Is it dead? The meter test is below: This part.
BC846BDW1T1SOT-3636 pins, onsemiNot recordedSOT-3636 pinsonsemi
- What it is
- Not recorded
- Maker
- onsemi
- Package
- SOT-363
- Pins
- 6
- Details
- equivalent 2x BC546B
- Source
- Published code list
Is it dead? The meter test is below: This part.
BC846BW(T1)SOT-3233 pins, KECNot recordedSOT-3233 pinsKEC
- What it is
- Not recorded
- Maker
- KEC
- Package
- SOT-323
- Pins
- 3
- Details
- Si-npn: GP, 80V, 100mA, 250mW, B=200..450, >100MHz
- Source
- Published code list
Is it dead? The meter test is below: This part.
BC846BWT1SOT-3233 pins, onsemiNot recordedSOT-3233 pinsonsemi
- What it is
- Not recorded
- Maker
- onsemi
- Package
- SOT-323
- Pins
- 3
- Details
- equivalent BC546B
- Source
- Published code list
Is it dead? The meter test is below: This part.
3 more parts have no package on record
SGM808B-5.5XKB5GVoltage supervisor, 5 pins, SG MicroVoltage supervisorNot recorded5 pinsSG Micro
- What it is
- Voltage supervisor
- Maker
- SG Micro
- Package
- Not recorded
- Pins
- 5
- Details
- Small Package, High Precision Voltage Detector
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Integrated circuit.
SGM893B-1.2XUDH4GVoltage supervisor, 4 pins, SG MicroVoltage supervisorNot recorded4 pinsSG Micro
- What it is
- Voltage supervisor
- Maker
- SG Micro
- Package
- Not recorded
- Pins
- 4
- Details
- Standard CMOS Voltage Detector ICs
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Integrated circuit.
SGM41105-442O31YXDH4GBattery protection IC, 4 pins, SG MicroBattery protection ICNot recorded4 pinsSG Micro
- What it is
- Battery protection IC
- Maker
- SG Micro
- Package
- Not recorded
- Pins
- 4
- Details
- Primary Protector and Switch with Shipping Mode for Tiny Li+/Poly Battery
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Integrated circuit.
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.
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.
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.
This part
Diode range and ohms range, part lifted.
Working, it reads
Depends on what it is. The datasheet, or an identical part, says.
Dead, it reads
- Between two pins, the same reading both ways, near 0 V with a continuous beep: shorted.
- Open between every pair of pins: failed open, or a part that reads open when working.
- On the board
- this is a first look only: the meter reads every path between those pins, and a short can be a neighbour. Lift one leg before you condemn it.
- Compare:
- If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.
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