SMD code R1G
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.
R1G is a resistor marking
0.1 Ω
0.1 Ω resistor, 2%
The R stands in for the decimal point, which is how sub-ohm and fractional values are printed. G is the tolerance, ±2%.
Check it with a meter
Lift one end and measure across it. A good one reads 0.1 Ω within 2%. Measuring it in circuit reads the parallel combination of everything around it, which is almost always lower, never higher: well above 0.1 Ω on the board is a fault. Open, or well above 0.1 Ω, means it has failed: burnt, cracked or corroded. That does not change what to fit: the marking still says 0.1 Ω. A burnt resistor usually means the part it feeds drew too much, so find that before fitting a new one.
On a transistor or diode body (SOT-23, SOT-23-5, SOT-89-5), R1G is a part code instead. Those parts are listed below.
8 parts are printed R1G
Not sure which one you have?
Answer up to 4 quick questions and these 8 parts are ranked, with a meter test that settles it. It works on a dead part too.
SSTA06SOT-23NPN transistor, 3 pins, ROHMNPN transistorSOT-233 pinsROHM
- What it is
- NPN transistor
- Maker
- ROHM
- Package
- SOT-23
- Pins
- 3
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: NPN transistor.
ADR02AKSZ-REEL7SOT-3535 pins, Analog DevicesNot recordedSOT-3535 pinsAnalog Devices
- What it is
- Not recorded
- Maker
- Analog Devices
- Package
- SOT-353
- Pins
- 5
- Source
- Published code list
Is it dead? The meter test is below: This part.
ADR02AUJZ-REEL7SOT-23-55 pins, Analog DevicesNot recordedSOT-23-55 pinsAnalog Devices
- What it is
- Not recorded
- Maker
- Analog Devices
- Package
- SOT-23-5
- Pins
- 5
- Source
- Published code list
Is it dead? The meter test is below: This part.
CD214A-R1400SMARectifier, 2 pins, BournsRectifierSMA2 pinsBourns
- What it is
- Rectifier
- Maker
- Bourns
- Package
- SMA
- Pins
- 2
- Details
- Si-diode: Rect, 400V, 1A, Vf<1V(1A), <12pF
- Source
- Published code list
Is it dead? The meter test is below: Silicon diode.
CM7R250-16A-TSOT-23LDO regulator, 3 pins, Canaan MicroelectronicsLDO regulatorSOT-233 pinsCanaan Microelectronics
- What it is
- LDO regulator
- Maker
- Canaan Microelectronics
- Package
- SOT-23
- Pins
- 3
- Details
- Linear voltage regulator IC: LDO, 1.65V±3%, 150mA
- Source
- Published code list
Is it dead? The meter test is below: Voltage regulator.
MMSTA06SOT-23NPN transistor, 3 pins, ROHMNPN transistorSOT-233 pinsROHM
- What it is
- NPN transistor
- Maker
- ROHM
- Package
- SOT-23
- Pins
- 3
- Details
- 80V, 0.5A, General Purpose NPN Bipolar Transistor
- Source
- Published code list
Is it dead? The meter test is below: NPN transistor.
RP105N131DSOT-23-5LDO regulator, 5 pins, RicohLDO regulatorSOT-23-55 pinsRicoh
- What it is
- LDO regulator
- Maker
- Ricoh
- Package
- SOT-23-5
- Pins
- 5
- Details
- Linear voltage regulator IC: LDO, 1.3V±15mV, 400mA, +CE, CL
- Source
- Published code list
Is it dead? The meter test is below: Voltage regulator.
RS1004FLSOD-123F2 pins, Won-Top ElectronicsNot recordedSOD-123F2 pinsWon-Top Electronics
- What it is
- Not recorded
- Maker
- Won-Top Electronics
- Package
- SOD-123F
- Pins
- 2
- Details
- Diode: Fast recov. rectif, 400V, 1A, Vf=1.3V(1A), 150ns
- Source
- Published code list
Is it dead? The meter test is below: Silicon diode.
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.
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.
Silicon diode
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.
Voltage regulator
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.
Printed with a code easy to misread as R1G
One character differs, and it is one that is easy to confuse under a lamp. Each code has a page of its own.
Did you find your part?
Open this in the search to correct a character or try another package.