SMD code 41-
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.
60 parts are printed 41-
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.
AO6401ASOT-23-6P-channel MOSFET, 6 pins, Alpha & Omega SemiconductorP-channel MOSFETSOT-23-66 pinsAlpha & Omega Semiconductor
- What it is
- P-channel MOSFET
- Maker
- Alpha & Omega Semiconductor
- Package
- SOT-23-6
- Pins
- 6
- Details
- P-channel MOSFET (8-60 V)
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: P-channel MOSFET.
AO6401ALSOT-23-6P-channel MOSFET, 6 pins, Alpha & Omega SemiconductorP-channel MOSFETSOT-23-66 pinsAlpha & Omega Semiconductor
- What it is
- P-channel MOSFET
- Maker
- Alpha & Omega Semiconductor
- Package
- SOT-23-6
- Pins
- 6
- Details
- P-channel MOSFET (8-60 V)
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: P-channel MOSFET.
BAT41JFILMSOD-323Schottky diode, 2 pins, STMicroelectronicsSchottky diodeSOD-3232 pinsSTMicroelectronics
- What it is
- Schottky diode
- Maker
- STMicroelectronics
- Package
- SOD-323
- Pins
- 2
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Schottky diode.
BAT41KFILMSOD-523Schottky diode, 2 pins, STMicroelectronicsSchottky diodeSOD-5232 pinsSTMicroelectronics
- What it is
- Schottky diode
- Maker
- STMicroelectronics
- Package
- SOD-523
- Pins
- 2
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Schottky diode.
DTC044EEBSOT-416Digital transistor (NPN, resistors built in), 3 pins, ROHMDigital transistor (NPN, resistors built in)SOT-4163 pinsROHM
- What it is
- Digital transistor (NPN, resistors built in)
- Maker
- ROHM
- Package
- SOT-416
- Pins
- 3
- Details
- NPN 100mA 50V Digital Transistor (Bias Resistor Built-in Transistor)
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Digital transistor.
DTC044EMSOT-723Digital transistor (NPN, resistors built in), 3 pins, ROHMDigital transistor (NPN, resistors built in)SOT-7233 pinsROHM
- What it is
- Digital transistor (NPN, resistors built in)
- Maker
- ROHM
- Package
- SOT-723
- Pins
- 3
- Details
- NPN 100mA 50V Digital Transistor (Bias Resistor Built-in Transistor)
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Digital transistor.
DTC044EUBSOT-323Digital transistor (NPN, resistors built in), 3 pins, ROHMDigital transistor (NPN, resistors built in)SOT-3233 pinsROHM
- What it is
- Digital transistor (NPN, resistors built in)
- Maker
- ROHM
- Package
- SOT-323
- Pins
- 3
- Details
- NPN 100mA 50V Digital Transistor (Bias Resistor Built-in Transistor)
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Digital transistor.
PMBFJ111SOT-23JFET, 3 pins, NXPJFETSOT-233 pinsNXP
- What it is
- JFET
- Maker
- NXP
- Package
- SOT-23
- Pins
- 3
- Details
- N-channel junction FETs
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: JFET.
RB068MM-40SOD-123FSchottky diode, 2 pins, ROHMSchottky diodeSOD-123F2 pinsROHM
- What it is
- Schottky diode
- Maker
- ROHM
- Package
- SOD-123F
- Pins
- 2
- Details
- Schottky Barrier Diode
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Schottky diode.
RB068MM-40TFSOD-123FSchottky diode, 2 pins, ROHMSchottky diodeSOD-123F2 pinsROHM
- What it is
- Schottky diode
- Maker
- ROHM
- Package
- SOD-123F
- Pins
- 2
- Details
- Schottky Barrier Diode (AEC-Q101 qualified)
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Schottky diode.
WPM2341A-3SOT-23P-channel MOSFET, 3 pins, WillsemiP-channel MOSFETSOT-233 pinsWillsemi
- What it is
- P-channel MOSFET
- Maker
- Willsemi
- Package
- SOT-23
- Pins
- 3
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: P-channel MOSFET.
4 more parts have no package on record
LD39130SJ41RLDO regulator, STMicroelectronicsLDO regulatorNot recordedNot recordedSTMicroelectronics
- What it is
- LDO regulator
- Maker
- STMicroelectronics
- Package
- Not recorded
- Pins
- Not recorded
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Voltage regulator.
NUF4001MUESD protection diode, onsemiESD protection diodeNot recordedNot recordedonsemi
- What it is
- ESD protection diode
- Maker
- onsemi
- Package
- Not recorded
- Pins
- Not recorded
- Details
- EMI Filter, 4 Channel, with Integrated ESD Protection
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: TVS or ESD protection diode.
SGM2038-1.5XUDY4GLDO regulator, 4 pins, SG MicroLDO regulatorNot recorded4 pinsSG Micro
- What it is
- LDO regulator
- Maker
- SG Micro
- Package
- Not recorded
- Pins
- 4
- Details
- 1.5 V output, 500mA, Low Noise, Very Low Dropout Bias Rail CMOS Voltage Regulator
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Voltage regulator.
SGM2045LC-0.7XXDH4GLDO regulator, 4 pins, SG MicroLDO regulatorNot recorded4 pinsSG Micro
- What it is
- LDO regulator
- Maker
- SG Micro
- Package
- Not recorded
- Pins
- 4
- Details
- 0.7 V output, 300mA, Low VIN, Ultra-Low Noise, Start-Up Current, High PSRR Linear Regulator
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Voltage regulator.
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.
P-channel MOSFET
Diode range, part lifted. Test drain to source first, then short gate to source and test again.
Working, it reads
Red probe on the drain, black on the source: about 0.4 to 0.9 V, the body diode. Open the other way. The gate reads open to both other pins, both ways.
Dead, it reads
- Drain to source the same both ways, near 0 V with a continuous beep, and still so after shorting gate to source: shorted. The classic failure.
- The gate reads low to source or drain: gate shorted. Often all three pins end up shorted together.
- No body diode at all: failed open.
- On the board
- the gate usually has a resistor to the source, so gate to source reads that resistor, which is not a fault. Lift a leg to be sure.
- Compare:
- If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
- Watch for:
- The diode range can charge the gate enough to turn the part on, and then drain to source reads near 0 both ways on a good part. Short gate to source and test again before you condemn it.
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.
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.
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.
TVS or ESD protection diode
Diode range, from the protected line to ground, part lifted if you can.
Working, it reads
A one-way part reads about 0.6 to 0.8 V forward and open in reverse. A two-way part reads open both ways. Arrays with several lines read as the datasheet's diagram draws them.
Dead, it reads
- From the line to ground, the same reading both ways, near 0 V with a continuous beep: shorted.
- A reading both ways on a one-way part: leaky.
- A one-way part open both ways: failed open.
- On the board
- , a line reading shorted to ground can be this part or anything else on that line. Lift it: if the short goes with it, it has failed.
- Compare:
- The same part on the next line or connector pin is the healthy reading to compare with.
- Watch for:
- A two-way part reads open both ways when it is good, exactly like one that has failed open. The meter cannot tell them apart; an identical part on the next line can.
A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.
JFET
Ohms range for drain to source, diode range for the gate, part lifted.
Working, it reads
Drain to source conducts both ways at a few hundred ohms, depending on the part, and some meters beep on it. The gate reads one junction to drain and to source, about 0.6 to 0.7 V, and open the other way.
Dead, it reads
- The gate the same both ways to drain or source, near 0 V with a continuous beep: gate shorted.
- Drain to source open: the channel has 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:
- Drain to source resistance varies from part to part. An identical part elsewhere on the board shows what is normal.
- Watch for:
- A good channel can beep like a short between drain and source. That is normal; the gate junction says whether it has failed.
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 41-
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 41-
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 1,175 more parts.
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