SMD code G1-
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.
162 parts are printed G1-
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.
FMBT5551-Q1SOT-23NPN transistor, 3 pins, Formosa MicrosemiNPN transistorSOT-233 pinsFormosa Microsemi
- What it is
- NPN transistor
- Maker
- Formosa Microsemi
- Package
- SOT-23
- Pins
- 3
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: NPN transistor.
FMG1ASOT-23-5Digital transistor (resistors built in), 5 pins, ROHMDigital transistor (resistors built in)SOT-23-55 pinsROHM
- What it is
- Digital transistor (resistors built in)
- Maker
- ROHM
- Package
- SOT-23-5
- Pins
- 5
- Details
- Emitter common(dual digital transistors)
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Digital transistor.
HMMBT5551TSOT-523NPN transistor, 3 pins, HXYNPN transistorSOT-5233 pinsHXY
- What it is
- NPN transistor
- Maker
- HXY
- Package
- SOT-523
- Pins
- 3
- Details
- Bipolar transistor, 160 V, 0.6 A
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: NPN transistor.
LMBT5551DW1T1GSOT-363Transistor, 6 pins, LRCTransistorSOT-3636 pinsLRC
- What it is
- Transistor
- Maker
- LRC
- Package
- SOT-363
- Pins
- 6
- Details
- Bipolar transistor, N+N, IC 600 mA, VCEO 140 V
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Bipolar transistor.
LMBT5551LT1GSOT-23NPN transistor, 3 pins, LRCNPN transistorSOT-233 pinsLRC
- What it is
- NPN transistor
- Maker
- LRC
- Package
- SOT-23
- Pins
- 3
- Details
- Bipolar transistor, NPN, IC 600 mA, VCEO 160 V
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: NPN transistor.
LMBT5551LT3GSOT-23NPN transistor, 3 pins, LRCNPN transistorSOT-233 pinsLRC
- What it is
- NPN transistor
- Maker
- LRC
- Package
- SOT-23
- Pins
- 3
- Details
- Bipolar transistor, NPN, IC 600 mA, VCEO 160 V
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: NPN transistor.
MMBT5551SOT-23NPN transistor, 3 pins, Taitron ComponentsNPN transistorSOT-233 pinsTaitron Components
- What it is
- NPN transistor
- Maker
- Taitron Components
- Package
- SOT-23
- Pins
- 3
- Details
- NPN bipolar transistor
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: NPN transistor.
MMBT5551-3LSOT-23NPN transistor, 3 pins, Galaxy MicroelectronicsNPN transistorSOT-233 pinsGalaxy Microelectronics
- What it is
- NPN transistor
- Maker
- Galaxy Microelectronics
- Package
- SOT-23
- Pins
- 3
- Details
- 160V, 0.6A, General Purpose NPN Bipolar Transistor
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: NPN transistor.
MMBT5551-CSOT-23Transistor, 3 pins, SeCoSTransistorSOT-233 pinsSeCoS
- What it is
- Transistor
- Maker
- SeCoS
- Package
- SOT-23
- Pins
- 3
- Details
- Bipolar transistor
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Bipolar transistor.
MMBT5551-HFSOT-23NPN transistor, 3 pins, ComchipNPN transistorSOT-233 pinsComchip
- What it is
- NPN transistor
- Maker
- Comchip
- Package
- SOT-23
- Pins
- 3
- Details
- 160 V, 0.6 A NPN transistor
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: NPN transistor.
MMBT5551-LSOT-23Transistor, 3 pins, YFWTransistorSOT-233 pinsYFW
- What it is
- Transistor
- Maker
- YFW
- Package
- SOT-23
- Pins
- 3
- Details
- Bipolar transistor
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Bipolar transistor.
MMBT5551-P2-HFSOT-23NPN transistor, 3 pins, ComchipNPN transistorSOT-233 pinsComchip
- What it is
- NPN transistor
- Maker
- Comchip
- Package
- SOT-23
- Pins
- 3
- Details
- 160 V, 0.6 A NPN transistor
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: NPN transistor.
MMBT5551LSOT-23NPN transistor, 3 pins, onsemiNPN transistorSOT-233 pinsonsemi
- What it is
- NPN transistor
- Maker
- onsemi
- Package
- SOT-23
- Pins
- 3
- Details
- High Voltage Transistors
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: NPN transistor.
MMBT5551LT1GSOT-23NPN transistor, 3 pins, HXYNPN transistorSOT-233 pinsHXY
- What it is
- NPN transistor
- Maker
- HXY
- Package
- SOT-23
- Pins
- 3
- Details
- Bipolar transistor, 160 V, 0.6 A
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: NPN transistor.
1 more part has no package on record
HFCN-2000+RF filter, Mini-CircuitsRF filterNot recordedNot recordedMini-Circuits
- What it is
- RF filter
- Maker
- Mini-Circuits
- Package
- Not recorded
- Pins
- Not recorded
- Details
- LTCC filter, 2260-6250 MHz
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: This part.
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.
Digital transistor
Ohms range, part lifted. The datasheet gives the built-in resistors: R1 in series with the base, R2 from base to emitter.
Working, it reads
Base to emitter reads about R1 plus R2 either way round, about 20 kΩ on a 10 k and 10 k part, give or take their wide tolerance. Collector to emitter reads open. A part with no R2 reads a junction behind R1 one way instead.
Dead, it reads
- Collector to emitter the same both ways, near 0 Ω with a continuous beep: shorted.
- From the base, open or far above R1 plus R2: R1 has failed. Static damage shows here most often.
- Base to emitter near 0 Ω: failed short.
- 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:
- The readings depend on the resistor values, so an identical part elsewhere on the board is the surest reference. Measure it the same way.
- Watch for:
- On the diode range a good part with 10 kΩ resistors reads open on every pair, so a good part looks dead there. Use the ohms range.
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.
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.
Did you find your part?
Open this in the search to correct a character or try another package.