SMD code 51F
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.
51F on a chip resistor
33.2 MΩ
33.2 MΩ resistor, 1%
EIA-96 precision code: 51 selects 3.32 from the E96 series and F multiplies by 10000000. These are 1% parts.
Check it with a meter
Lift one end and measure across it. A good one reads 33.2 MΩ within 1%. Measuring it in circuit reads the parallel combination of everything around it, which is almost always lower, never higher: well above 33.2 MΩ on the board is a fault. Open, or well above 33.2 MΩ, means it has failed: burnt, cracked or corroded. That does not change what to fit: the marking still says 33.2 MΩ. 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-23-5, USP-6C, SOD-882), 51F is a part code instead. Those parts are listed below.
8 parts are printed 51F
Not sure which one you have?
Answer up to 4 quick questions and these 8 parts are ranked, with a meter test that settles it. It works on a dead part too.
ES05DTGFBHASOD-882ESD protection diode, 2 pins, ETEKESD protection diodeSOD-8822 pinsETEK
- What it is
- ESD protection diode
- Maker
- ETEK
- Package
- SOD-882
- Pins
- 2
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: TVS or ESD protection diode.
GALI-51F+SOT-89RF amplifier (MMIC), 3 pins, Mini-CircuitsRF amplifier (MMIC)SOT-893 pinsMini-Circuits
- What it is
- RF amplifier (MMIC)
- Maker
- Mini-Circuits
- Package
- SOT-89
- Pins
- 3
- Details
- MMIC amplifier, DC-4 GHz
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: RF amplifier.
WS6151KF-ATSOD-882ESD protection diode, 2 pins, WayonESD protection diodeSOD-8822 pinsWayon
- What it is
- ESD protection diode
- Maker
- Wayon
- Package
- SOD-882
- Pins
- 2
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: TVS or ESD protection diode.
WS61515FSOD-882ESD protection diode, 2 pins, WayonESD protection diodeSOD-8822 pinsWayon
- What it is
- ESD protection diode
- Maker
- Wayon
- Package
- SOD-882
- Pins
- 2
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: TVS or ESD protection diode.
Gali-51FSOT-89RF amplifier (MMIC), 3 pins, Mini-CircuitsRF amplifier (MMIC)SOT-893 pinsMini-Circuits
- What it is
- RF amplifier (MMIC)
- Maker
- Mini-Circuits
- Package
- SOT-89
- Pins
- 3
- Details
- Lin-IC: RF amplifier, DC..4GHz, 13,3dB (50Ω)
- Source
- Published code list
Is it dead? The meter test is below: RF amplifier.
NNCD5.1FSOT-23ESD protection diode, 3 pins, RenesasESD protection diodeSOT-233 pinsRenesas
- What it is
- ESD protection diode
- Maker
- Renesas
- Package
- SOT-23
- Pins
- 3
- Details
- ElectroStatic Discharge Protection diode: Dual, Vbr=4.84..5.37V, Izt=5mA, 200mW
- Source
- Published code list
Is it dead? The meter test is below: TVS or ESD protection diode.
RP100N191DSOT-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, LN, 1.9V±0.8%, 200mA, +CE, CL
- Source
- Published code list
Is it dead? The meter test is below: Voltage regulator.
1 more part has no package on record
ULC0511CDNESD protection diode, LeiditechESD protection diodeNot recordedNot recordedLeiditech
- What it is
- ESD protection diode
- Maker
- Leiditech
- Package
- Not recorded
- Pins
- Not recorded
- Details
- ESD protection diode, VRWM 5 V, Cj 0.3 pF
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: TVS or ESD protection diode.
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.
RF amplifier
Voltage, board powered, on the output pin that the bias resistor or choke feeds.
Working, it reads
The output pin sits at the device voltage the datasheet gives, a few volts, below the supply.
Dead, it reads
- Output pin at 0 V, or near 0 Ω to ground with the power off: shorted inside.
- Output pin at the full supply voltage: open inside, no current flowing.
- On the board:
- Measured on the board with power on; the bias network is part of the reading.
- 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 figures depend on the part and its bias resistor. The datasheet gives both.
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.
Printed with a code easy to misread as 51F
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 51F
For a marking with its end worn or burnt off. Each code has a page of its own.
Did you find your part?
Open this in the search to correct a character or try another package.