SMD code FY in SMB
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.
1 part in SMB is printed FY
Not sure which one you have?
Answer up to 4 quick questions and these 25 parts are ranked, with a meter test that settles it. It works on a dead part too.
SM6T100ASMBTVS diode, MDE SemiconductorTVS diodeMDE Semiconductor
- What it is
- TVS diode
- Maker
- MDE Semiconductor
- Package
- SMB
- Pins
- 2
- Details
- 600 W TVS diode, unidirectional
- Source
- Published code list
Is it dead? The meter test is below: TVS or ESD protection diode.
14 more parts have no package on record. Nothing rules them out, so they stay.
MM5Z3V6BZener diode, Formosa MicrosemiZener diodeFormosa Microsemi
- What it is
- Zener diode
- Maker
- Formosa Microsemi
- Package
- Not recorded
- Pins
- Not recorded
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Zener diode.
MM5Z3V6B-Q1Zener diode, Formosa MicrosemiZener diodeFormosa Microsemi
- What it is
- Zener diode
- Maker
- Formosa Microsemi
- Package
- Not recorded
- Pins
- Not recorded
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Zener diode.
RQ5L030ATP-channel MOSFET, ROHMP-channel MOSFETROHM
- What it is
- P-channel MOSFET
- Maker
- ROHM
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Pch -60V -3.0A Small Signal MOSFET
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: P-channel MOSFET.
BD48L30GVoltage supervisor, ROHMVoltage supervisorROHM
- What it is
- Voltage supervisor
- Maker
- ROHM
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Voltage Detector
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
BU45L262GVoltage supervisor, ROHMVoltage supervisorROHM
- What it is
- Voltage supervisor
- Maker
- ROHM
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Voltage detector IC: 2.6V±1%, -Reset ODO, Rdt=200ms
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
FSA2156FHXFairchild SemiconductorNot recordedFairchild Semiconductor
- What it is
- Not recorded
- Maker
- Fairchild Semiconductor
- Package
- Not recorded
- Pins
- Not recorded
- Details
- CMOS logic IC: Single-pole/single-throw analog switch
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
FSA2156P6XFairchild SemiconductorNot recordedFairchild Semiconductor
- What it is
- Not recorded
- Maker
- Fairchild Semiconductor
- Package
- Not recorded
- Pins
- Not recorded
- Details
- CMOS logic IC: Single-pole/single-throw analog switch
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
IXD5127C52ANRVoltage supervisor, IXYSVoltage supervisorIXYS
- What it is
- Voltage supervisor
- Maker
- IXYS
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Voltage detector IC: 5.2V±0.8%, -Reset PPO, -MR, 50ms Rt delay
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
IXD5127N52FNRVoltage supervisor, IXYSVoltage supervisorIXYS
- What it is
- Voltage supervisor
- Maker
- IXYS
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Voltage detector IC: 5.2V±0.8%, +Reset ODO, -MR, 50ms Rt delay
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
KDZ3.3VVYZener diode, KECZener diodeKEC
- What it is
- Zener diode
- Maker
- KEC
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Zener diode: 3.25..3.50V, Izt=5mA, Zzt=130, 100mW
- Source
- Published code list
Is it dead? The meter test is below: Zener diode.
KTA2013F-YPNP transistor, KECPNP transistorKEC
- What it is
- PNP transistor
- Maker
- KEC
- Package
- Not recorded
- Pins
- Not recorded
- Details
- PNP transistor: AF, Sw, 20V, 150mA, 50mW, B=120..240, >80MHz
- Source
- Published code list
Is it dead? The meter test is below: PNP transistor.
RP300K28DCVoltage supervisor, RicohVoltage supervisorRicoh
- What it is
- Voltage supervisor
- Maker
- Ricoh
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Voltage detector IC: 2.8V±1%, +Reset PPO, -MR, Rdt=200ms
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
XC6127C52ANRVoltage supervisor, TorexVoltage supervisorTorex
- What it is
- Voltage supervisor
- Maker
- Torex
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Voltage detector IC: 5.2V±0.8%, -Reset PPO, -MR, Rdt=50ms
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
XC6127N52FNRVoltage supervisor, TorexVoltage supervisorTorex
- What it is
- Voltage supervisor
- Maker
- Torex
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Voltage detector IC: 5.2V±0.8%, +Reset ODO, -MR, Rdt=50ms
- 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.
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.
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.
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.
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.
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.
Codes that begin with FY
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 7 more parts.
Did you find your part?
Open this in the search to correct a character or try another package.