SMD code M4 in DFN
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.
2 parts in DFN are printed M4
Not sure which one you have?
Answer up to 4 quick questions and these 29 parts are ranked, with a meter test that settles it. It works on a dead part too.
R3117K213ADFNVoltage supervisor, RicohVoltage supervisorNot recordedRicoh
- What it is
- Voltage supervisor
- Maker
- Ricoh
- Package
- DFN
- Pins
- Not recorded
- Details
- Voltage detector IC: 2.1V±1%, -Reset ODO, Sense
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
RP114K221BDFNLDO regulator, RicohLDO regulatorNot recordedRicoh
- What it is
- LDO regulator
- Maker
- Ricoh
- Package
- DFN
- Pins
- Not recorded
- Details
- Linear voltage regulator IC: LDO, 2.2V±1%, 300mA, +CE
- Source
- Published code list
Is it dead? The meter test is below: Voltage regulator.
13 more parts have no package on record. Nothing rules them out, so they stay.
FM4004-AWRectifier, Formosa MicrosemiRectifierNot recordedFormosa Microsemi
- What it is
- Rectifier
- Maker
- Formosa Microsemi
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Rectifier diode
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Silicon diode.
LDTC114WET1GDigital transistor (NPN, resistors built in), LRCDigital transistor (NPN, resistors built in)Not recordedLRC
- What it is
- Digital transistor (NPN, resistors built in)
- Maker
- LRC
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Digital transistor (bias resistors built in), NPN, IC 100 mA, VCEO 50 V
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Digital transistor.
MMBZ5259BWSZener diode, Taitron ComponentsZener diodeNot recordedTaitron Components
- What it is
- Zener diode
- Maker
- Taitron Components
- Package
- Not recorded
- Pins
- Not recorded
- Details
- SMD Zener Diodes (Three Terminals) - 200mW
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Zener diode.
WRM4Schottky diode, WayonSchottky diodeNot recordedWayon
- What it is
- Schottky diode
- Maker
- Wayon
- Package
- Not recorded
- Pins
- Not recorded
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Schottky diode.
2SA812-4PNP transistor, NEC ElectronicsPNP transistorNot recordedNEC Electronics
- What it is
- PNP transistor
- Maker
- NEC Electronics
- Package
- Not recorded
- Pins
- Not recorded
- Details
- PNP transistor: GP, AF, 60V, 100mA, 200mW, B=90..180, 180MHz
- Source
- Published code list
Is it dead? The meter test is below: PNP transistor.
2SA812A-4PNP transistor, NEC ElectronicsPNP transistorNot recordedNEC Electronics
- What it is
- PNP transistor
- Maker
- NEC Electronics
- Package
- Not recorded
- Pins
- Not recorded
- Details
- PNP transistor: GP, AF, 60V, 100mA, 200mW, B=90..180, 180MHz
- Source
- Published code list
Is it dead? The meter test is below: PNP transistor.
2SA812AM43 pins, RenesasNot recorded3 pinsRenesas
- What it is
- Not recorded
- Maker
- Renesas
- Package
- Not recorded
- Pins
- 3
- Source
- Published code list
Is it dead? The meter test is below: This part.
2SA1179-4PNP transistor, Sanyo ElectricPNP transistorNot recordedSanyo Electric
- What it is
- PNP transistor
- Maker
- Sanyo Electric
- Package
- Not recorded
- Pins
- Not recorded
- Details
- PNP transistor: GP, AF, 55V, 150mA, 200mW, B=90..180, 180MHz
- Source
- Published code list
Is it dead? The meter test is below: PNP transistor.
2SA1179-M4onsemiNot recordedNot recordedonsemi
- What it is
- Not recorded
- Maker
- onsemi
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Si-pnp: GP, AF, 55V, 150mA, 200mW, B=90..180, 180MHz
- Source
- Published code list
Is it dead? The meter test is below: This part.
AP8821N-44GIVoltage supervisor, Anwell SemiconductorVoltage supervisorNot recordedAnwell Semiconductor
- What it is
- Voltage supervisor
- Maker
- Anwell Semiconductor
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Voltage detector IC: 4.4V±2%, -Reset ODO, H-free
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
AP8821N-44GSVoltage supervisor, Anwell SemiconductorVoltage supervisorNot recordedAnwell Semiconductor
- What it is
- Voltage supervisor
- Maker
- Anwell Semiconductor
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Voltage detector IC: 4.4V±2%, -Reset ODO, H-free
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
AP8821N-44PIVoltage supervisor, Anwell SemiconductorVoltage supervisorNot recordedAnwell Semiconductor
- What it is
- Voltage supervisor
- Maker
- Anwell Semiconductor
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Voltage detector IC: 4.4V±2%, -Reset ODO
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
AP8821N-44PSVoltage supervisor, Anwell SemiconductorVoltage supervisorNot recordedAnwell Semiconductor
- What it is
- Voltage supervisor
- Maker
- Anwell Semiconductor
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Voltage detector IC: 4.4V±2%, -Reset ODO
- Source
- Published code list
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.
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.
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.
Zener diode
Diode range for the forward check, part lifted, red probe on the anode. A bench supply for the Zener voltage.
Working, it reads
About 0.6 to 0.8 V forward and open in reverse on the diode range. Its Zener voltage shows only on a supply: feed it through a resistor that sets about 5 mA, cathode to positive, read quickly, and it should hold near its rated voltage.
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, forward too: failed open.
- Holds well off its rated voltage on the supply test: drifted.
- A soft knee, or a voltage that creeps on the supply test: 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 meter's diode range stops at about 2 to 3 V, so almost every Zener reads open in reverse on it, good or bad; a 3 V meter may just show a 2.4 or 2.7 V part. Above about 3 V the meter cannot tell a Zener from a plain diode.
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.
PNP transistor
Diode range, part lifted or its base leg off the pad.
Working, it reads
Black 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.
Codes that begin with M4
For a marking with its end worn or burnt off. Each code has a page of its own.
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