SMD code J18
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.
10 parts are printed J18
Not sure which one you have?
Answer up to 4 quick questions and these 10 parts are ranked, with a meter test that settles it. It works on a dead part too.
CH858BGPSOT-23PNP transistor, 3 pins, ChenmkoPNP transistorSOT-233 pinsChenmko
- What it is
- PNP transistor
- Maker
- Chenmko
- Package
- SOT-23
- Pins
- 3
- Details
- PNP General Purpose Transistor, 30 V, 0.1 A
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: PNP transistor.
CH858BPT-QSOT-23PNP transistor, 3 pins, Chenmko EnterprisePNP transistorSOT-233 pinsChenmko Enterprise
- What it is
- PNP transistor
- Maker
- Chenmko Enterprise
- Package
- SOT-23
- Pins
- 3
- Details
- PNP transistor: AF, Sw, 30V, 100mA, B=125..250, 200MHz
- Source
- Published code list
Is it dead? The meter test is below: PNP transistor.
DAM04SMA18SMAESD protection diode, 2 pins, HitachiESD protection diodeSMA2 pinsHitachi
- What it is
- ESD protection diode
- Maker
- Hitachi
- Package
- SMA
- Pins
- 2
- Details
- ElectroStatic Discharge Protection diode: Vrwm=14.5V, Vbr=16.8..19.1V, Ipp=15.1A, 400W(1ms)
- Source
- Published code list
Is it dead? The meter test is below: TVS or ESD protection diode.
DAM06SMB18SMBESD protection diode, 2 pins, HitachiESD protection diodeSMB2 pinsHitachi
- What it is
- ESD protection diode
- Maker
- Hitachi
- Package
- SMB
- Pins
- 2
- Details
- ElectroStatic Discharge Protection diode: Vrwm=14.5V, Vbr=16.8..19.1V, Ipp=22.6A, 600W(1ms)
- Source
- Published code list
Is it dead? The meter test is below: TVS or ESD protection diode.
DAM15SMC18SMCESD protection diode, 2 pins, HitachiESD protection diodeSMC2 pinsHitachi
- What it is
- ESD protection diode
- Maker
- Hitachi
- Package
- SMC
- Pins
- 2
- Details
- ElectroStatic Discharge Protection diode: Vrwm=14.5V, Vbr=16.8..19.1V, Ipp=56.6A, 1500W(1ms)
- Source
- Published code list
Is it dead? The meter test is below: TVS or ESD protection diode.
KIC73C18TSOT-23Voltage supervisor, 3 pins, KECVoltage supervisorSOT-233 pinsKEC
- What it is
- Voltage supervisor
- Maker
- KEC
- Package
- SOT-23
- Pins
- 3
- Details
- Voltage detector IC: 1.8V±1%, -Reset PPO, Rdt=100ms
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
R1154N118BSOT-23-55 pins, Nisshinbo Micro DevicesNot recordedSOT-23-55 pinsNisshinbo Micro Devices
- What it is
- Not recorded
- Maker
- Nisshinbo Micro Devices
- Package
- SOT-23-5
- Pins
- 5
- Details
- VR-IC: LDO, CE, 11.8V±2%, 150mA
- Source
- Published code list
Is it dead? The meter test is below: Voltage regulator.
RP111N181DSOT-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, 1.8V±0.8%, 500mA, +CE, CL
- Source
- Published code list
Is it dead? The meter test is below: Voltage regulator.
SO679RSOT-233 pins, Compagnie générale de télégraphie Sans Fil (Thomson-CSF)Not recordedSOT-233 pinsCompagnie générale de télégraphie Sans Fil (Thomson-CSF)
- What it is
- Not recorded
- Maker
- Compagnie générale de télégraphie Sans Fil (Thomson-CSF)
- Package
- SOT-23
- Pins
- 3
- Details
- equivalent BF679
- Source
- Published code list
Is it dead? The meter test is below: This part.
1 more part has no package on record
KIC73C18MVoltage supervisor, KECVoltage supervisorNot recordedNot recordedKEC
- What it is
- Voltage supervisor
- Maker
- KEC
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Voltage detector IC: 1.8V±1%, -Reset PPO, Rdt=100ms
- 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.
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.
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.
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 J18
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 J18
For a marking with its end worn or burnt off. Each code has a page of its own.
- J185N65G4M1
- J185N65G4Z1
- J18U1
- J181H1
- J181I1
- J181J1
- J181K1
- J181L1
- J181M1
- J181N1
- J181O1
- J181P1
- J181Q1
- J181R1
- J181S1
- J181T1
- J181U1
- J181V1
- J181W1
- J181X1
- J181Y1
- J181Z1
- J182H1
- J182I1
- J182J1
- J182K1
Codes not listed here are printed on 509 more parts.
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