SMD code 431
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.
431 on a chip resistor
430 Ω
430 Ω resistor, 5%
43 followed by 1 zero. Three digits is normally the 5% series. The same marking also reads as 430 pF on a capacitor or 430 µH on an inductor, and nothing in the code says which; the body of the part does.
Other readings of the same characters, most likely first
- 430 pF capacitor
- 430 µH inductor
Check it with a meter
Lift one end and measure across it. A good one reads 430 Ω within 5%. Measuring it in circuit reads the parallel combination of everything around it, which is almost always lower, never higher: well above 430 Ω on the board is a fault. Open, or well above 430 Ω, means it has failed: burnt, cracked or corroded. That does not change what to fit: the marking still says 430 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, SOIC-8, SOT-23-5), 431 is a part code instead. Those parts are listed below.
31 parts are printed 431
Not sure which one you have?
Answer up to 4 quick questions and these 31 parts are ranked, with a meter test that settles it. It works on a dead part too.
BL431SOT-23Voltage reference, 3 pins, Galaxy MicroelectronicsVoltage referenceSOT-233 pinsGalaxy Microelectronics
- What it is
- Voltage reference
- Maker
- Galaxy Microelectronics
- Package
- SOT-23
- Pins
- 3
- Details
- 2.5 V Voltage Reference
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Integrated circuit.
BL431-3LSOT-23Voltage reference, 3 pins, Galaxy MicroelectronicsVoltage referenceSOT-233 pinsGalaxy Microelectronics
- What it is
- Voltage reference
- Maker
- Galaxy Microelectronics
- Package
- SOT-23
- Pins
- 3
- Details
- 2.5 V Voltage Reference
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Integrated circuit.
BL431-ASOT-23Voltage reference, 3 pins, Galaxy MicroelectronicsVoltage referenceSOT-233 pinsGalaxy Microelectronics
- What it is
- Voltage reference
- Maker
- Galaxy Microelectronics
- Package
- SOT-23
- Pins
- 3
- Details
- 2.5 V Voltage Reference
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Integrated circuit.
BL431ESOT-89Voltage reference, 3 pins, Galaxy MicroelectronicsVoltage referenceSOT-893 pinsGalaxy Microelectronics
- What it is
- Voltage reference
- Maker
- Galaxy Microelectronics
- Package
- SOT-89
- Pins
- 3
- Details
- 2.5 V Voltage Reference
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Integrated circuit.
BL431E-ASOT-89Voltage reference, 3 pins, Galaxy MicroelectronicsVoltage referenceSOT-893 pinsGalaxy Microelectronics
- What it is
- Voltage reference
- Maker
- Galaxy Microelectronics
- Package
- SOT-89
- Pins
- 3
- Details
- 2.5 V Voltage Reference
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Integrated circuit.
BR431TSOT-89Voltage regulator, 3 pins, Blue RocketVoltage regulatorSOT-893 pinsBlue Rocket
- What it is
- Voltage regulator
- Maker
- Blue Rocket
- Package
- SOT-89
- Pins
- 3
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Voltage regulator.
GS431-TRSOT-23Voltage reference, 3 pins, GainsilVoltage referenceSOT-233 pinsGainsil
- What it is
- Voltage reference
- Maker
- Gainsil
- Package
- SOT-23
- Pins
- 3
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Integrated circuit.
TL431SOT-23Voltage reference, 3 pins, HXYVoltage referenceSOT-233 pinsHXY
- What it is
- Voltage reference
- Maker
- HXY
- Package
- SOT-23
- Pins
- 3
- Details
- Voltage reference, 0.1 A
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Integrated circuit.
TL431A-CSOT-23Voltage reference, 3 pins, SeCoSVoltage referenceSOT-233 pinsSeCoS
- What it is
- Voltage reference
- Maker
- SeCoS
- Package
- SOT-23
- Pins
- 3
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Integrated circuit.
TL431AFSOT-89Voltage reference, 3 pins, HTC KoreaVoltage referenceSOT-893 pinsHTC Korea
- What it is
- Voltage reference
- Maker
- HTC Korea
- Package
- SOT-89
- Pins
- 3
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Integrated circuit.
TL431ASFSOT-23Voltage reference, 3 pins, HTC KoreaVoltage referenceSOT-233 pinsHTC Korea
- What it is
- Voltage reference
- Maker
- HTC Korea
- Package
- SOT-23
- Pins
- 3
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Integrated circuit.
TL431BSOT-23Voltage reference, 3 pins, SeCoSVoltage referenceSOT-233 pinsSeCoS
- What it is
- Voltage reference
- Maker
- SeCoS
- Package
- SOT-23
- Pins
- 3
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Integrated circuit.
3 more parts have no package on record
ET431BETEKNot recordedNot recordedNot recordedETEK
- What it is
- Not recorded
- Maker
- ETEK
- Package
- Not recorded
- Pins
- Not recorded
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: This part.
TL431CFVoltage reference, HTC KoreaVoltage referenceNot recordedNot recordedHTC Korea
- What it is
- Voltage reference
- Maker
- HTC Korea
- Package
- Not recorded
- Pins
- Not recorded
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Integrated circuit.
TL431CSFVoltage reference, HTC KoreaVoltage referenceNot recordedNot recordedHTC Korea
- What it is
- Voltage reference
- Maker
- HTC Korea
- Package
- Not recorded
- Pins
- Not recorded
- 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.
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.
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.
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.
Printed with a code easy to misread as 431
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 431
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 41 more parts.
Did you find your part?
Open this in the search to correct a character or try another package.