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SMD code R1K

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.

R1K is a resistor marking

0.1 Ω

0.1 Ω resistor, 10%

The R stands in for the decimal point, which is how sub-ohm and fractional values are printed. K is the tolerance, ±10%. The same marking also reads as 0.1 µH on an inductor, and nothing in the code says which; the body of the part does.

Other readings of the same characters, most likely first

  • 0.1 µH inductor, 10%

Check it with a meter

Lift one end and measure across it. A good one reads 0.1 Ω within 10%. Measuring it in circuit reads the parallel combination of everything around it, which is almost always lower, never higher: well above 0.1 Ω on the board is a fault. Open, or well above 0.1 Ω, means it has failed: burnt, cracked or corroded. That does not change what to fit: the marking still says 0.1 Ω. 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-89-5, SMA, SOT-23), R1K is a part code instead. Those parts are listed below.

10 parts are printed R1K

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.

  • ADR03BKSZ-REEL7SOT-3535 pins, Analog DevicesNot recordedSOT-3535 pinsAnalog Devices
    What it is
    Not recorded
    Maker
    Analog Devices
    Package
    SOT-353
    Pins
    5
    Source
    Published code list

    Is it dead? The meter test is below: This part.

  • CD214A-R1800SMARectifier, 2 pins, BournsRectifierSMA2 pinsBourns
    What it is
    Rectifier
    Maker
    Bourns
    Package
    SMA
    Pins
    2
    Details
    Si-diode: Rect, 800V, 1A, Vf<1.25V(1A), <12pF
    Source
    Published code list

    Is it dead? The meter test is below: Silicon diode.

  • MMST6428SOT-23NPN transistor, 3 pins, ROHMNPN transistorSOT-233 pinsROHM
    What it is
    NPN transistor
    Maker
    ROHM
    Package
    SOT-23
    Pins
    3
    Details
    NPN transistor: GP, 60V, 200mA, 350mW, B=250..650, 100..700MHz
    Source
    Published code list

    Is it dead? The meter test is below: NPN transistor.

  • RP105N111DSOT-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, 1.1V±15mV, 400mA, +CE, CL
    Source
    Published code list

    Is it dead? The meter test is below: Voltage regulator.

  • RS1008FLSOD-123F2 pins, Won-Top ElectronicsNot recordedSOD-123F2 pinsWon-Top Electronics
    What it is
    Not recorded
    Maker
    Won-Top Electronics
    Package
    SOD-123F
    Pins
    2
    Details
    Diode: Fast recov. rectif, 800V, 1A, Vf=1.3V(1A), 500ns
    Source
    Published code list

    Is it dead? The meter test is below: Silicon diode.

  • SST6428SOT-23NPN transistor, 3 pins, ROHMNPN transistorSOT-233 pinsROHM
    What it is
    NPN transistor
    Maker
    ROHM
    Package
    SOT-23
    Pins
    3
    Details
    Si-npn: AF, 60V, 200mA, B=250..650, >100MHz
    Source
    Published code list

    Is it dead? The meter test is below: NPN transistor.

  • XC6368F173MRSOT-23-5DC-DC converter, 5 pins, TorexDC-DC converterSOT-23-55 pinsTorex
    What it is
    DC-DC converter
    Maker
    Torex
    Package
    SOT-23-5
    Pins
    5
    Details
    DC/DC voltage converter IC: PWM/PFM st-up, 1.7V±2.5%, 200mA, 300kHz, +CE, soft start
    Source
    Published code list

    Is it dead? The meter test is below: Integrated circuit.

  • XC9147A55DER-GUSP-6CDC-DC converter, 6 pins, TorexDC-DC converterUSP-6C6 pinsTorex
    What it is
    DC-DC converter
    Maker
    Torex
    Package
    USP-6C
    Pins
    6
    Details
    DC/DC voltage converter IC: PWM st-up, 3.0MHz, 5.5V±2%, 1.4A, CrL, CL, +CE
    Source
    Published code list

    Is it dead? The meter test is below: Integrated circuit.

  • XC9147A55DPR-GSOT-89-5DC-DC converter, 5 pins, TorexDC-DC converterSOT-89-55 pinsTorex
    What it is
    DC-DC converter
    Maker
    Torex
    Package
    SOT-89-5
    Pins
    5
    Details
    DC/DC voltage converter IC: PWM step-up, 3.0MHz, 5.5V±2%, 1.4A, CrL, CL, +CE
    Source
    Published code list

    Is it dead? The meter test is below: Integrated circuit.

  • 1 more part has no package on record
    • ADR03BUJZ-REEL75 pins, Analog DevicesNot recordedNot recorded5 pinsAnalog Devices
      What it is
      Not recorded
      Maker
      Analog Devices
      Package
      Not recorded
      Pins
      5
      Source
      Published code list

      Is it dead? The meter test is below: This part.

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.

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.

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.

NPN transistor

Diode range, part lifted or its base leg off the pad.

Working, it reads

Red 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.

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.

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.

Printed with a code easy to misread as R1K

One character differs, and it is one that is easy to confuse under a lamp. 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.