SMD marking

1Kin SOT-143

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.

Not sure which one you have?

Answer up to 4 quick questions and these 2 parts are ranked, with a meter test that settles it. It works on a dead part too.

The only part printed 1K in this package in our tables

BCV61B

What it is: Dual NPN transistor
Maker: Infineon
Package: SOT-143
Pins: 4
Details: 30 V, 100 mA NPN current-mirror double transistor
Source: From the manufacturer's datasheet

Is it dead?

Diode range, part lifted. Test each transistor on its own pins, as the datasheet's pinout gives them.

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:: 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.

Datasheet

Printed with a code easy to misread

This part is printed with a character that is easy to misread as what you typed. The odd one out is marked on each.

BF799printed LKRF transistor, InfineonRF transistorInfineon
Printed LK on the part. Easy to misread as 1K. Check that character with a loupe before you order anything.
What it is
RF transistor
Maker
Infineon
Package
Not recorded
Pins
Not recorded
Source
From the manufacturer's datasheet
Is it dead?
Diode range, part lifted or its base leg off the pad.
Working, it reads
From the base, one probe colour 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:
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.
Datasheetfor BF799, opens in a new tab

17 more parts have codes that begin with 1K

Codes that begin with 1K

For a marking with its end worn or burnt off. Each one shows its full printed code.

S1KLprinted 1KLRectifier, Taiwan SemiconductorRectifierNot recordedTaiwan Semiconductor
Printed 1KL. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
What it is
Rectifier
Maker
Taiwan Semiconductor
Package
Not recorded
Pins
Not recorded
Source
From the manufacturer's datasheet
Is it dead?
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:
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.
Datasheetfor S1KL, opens in a new tab
S1KLHprinted 1KLRectifier, Taiwan SemiconductorRectifierNot recordedTaiwan Semiconductor
Printed 1KL. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
What it is
Rectifier
Maker
Taiwan Semiconductor
Package
Not recorded
Pins
Not recorded
Source
From the manufacturer's datasheet
Is it dead?
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:
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.
Datasheetfor S1KLH, opens in a new tab
S1KLSprinted 1KLSRectifier, Taiwan SemiconductorRectifierNot recordedTaiwan Semiconductor
Printed 1KLS. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
What it is
Rectifier
Maker
Taiwan Semiconductor
Package
Not recorded
Pins
Not recorded
Source
From the manufacturer's datasheet
Is it dead?
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:
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.
Datasheetfor S1KLS, opens in a new tab
S1KLSHprinted 1KLSRectifier, Taiwan SemiconductorRectifierNot recordedTaiwan Semiconductor
Printed 1KLS. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
What it is
Rectifier
Maker
Taiwan Semiconductor
Package
Not recorded
Pins
Not recorded
Source
From the manufacturer's datasheet
Is it dead?
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:
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.
Datasheetfor S1KLSH, opens in a new tab
SN74AUP1G57DRLprinted 1KCLogic gate, 6 pins, Texas InstrumentsLogic gate6 pinsTexas Instruments
Printed 1KC. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
What it is
Logic gate
Maker
Texas Instruments
Package
Not recorded
Pins
6
Details
Low-Power Configurable Multiple-Function Gate
Source
From the manufacturer's datasheet
Is it dead?
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.
Datasheetfor SN74AUP1G57DRL, opens in a new tab
SN74AUP1G58DRLprinted 1KDLogic gate, 6 pins, Texas InstrumentsLogic gate6 pinsTexas Instruments
Printed 1KD. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
What it is
Logic gate
Maker
Texas Instruments
Package
Not recorded
Pins
6
Details
LOW-POWER CONFIGURABLE MULTIPLE-FUNCTION GATE
Source
From the manufacturer's datasheet
Is it dead?
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.
Datasheetfor SN74AUP1G58DRL, opens in a new tab
SN74AUP1G97DRLprinted 1K9Logic gate, 6 pins, Texas InstrumentsLogic gate6 pinsTexas Instruments
Printed 1K9. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
What it is
Logic gate
Maker
Texas Instruments
Package
Not recorded
Pins
6
Details
LOW-POWER CONFIGURABLE MULTIPLE-FUNCTION GATE
Source
From the manufacturer's datasheet
Is it dead?
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.
Datasheetfor SN74AUP1G97DRL, opens in a new tab
SN74AUP1G98DRLprinted 1KELogic gate, 6 pins, Texas InstrumentsLogic gate6 pinsTexas Instruments
Printed 1KE. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
What it is
Logic gate
Maker
Texas Instruments
Package
Not recorded
Pins
6
Details
LOW-POWER CONFIGURABLE MULTIPLE-FUNCTION GATE
Source
From the manufacturer's datasheet
Is it dead?
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.
Datasheetfor SN74AUP1G98DRL, opens in a new tab
SN74LVC1G57DRLprinted 1K2Logic gate, 6 pins, Texas InstrumentsLogic gate6 pinsTexas Instruments
Printed 1K2. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
What it is
Logic gate
Maker
Texas Instruments
Package
Not recorded
Pins
6
Details
Configurable Multiple-Function Gate
Source
From the manufacturer's datasheet
Is it dead?
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.
Datasheetfor SN74LVC1G57DRL, opens in a new tab
SN74LVC1G58DRLprinted 1K3Logic gate, 6 pins, Texas InstrumentsLogic gate6 pinsTexas Instruments
Printed 1K3. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
What it is
Logic gate
Maker
Texas Instruments
Package
Not recorded
Pins
6
Details
Configurable Multiple-Function Gate
Source
From the manufacturer's datasheet
Is it dead?
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.
Datasheetfor SN74LVC1G58DRL, opens in a new tab
SN74LVC1G97DRLprinted 1K4Logic gate, 6 pins, Texas InstrumentsLogic gate6 pinsTexas Instruments
Printed 1K4. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
What it is
Logic gate
Maker
Texas Instruments
Package
Not recorded
Pins
6
Details
Configurable Multiple-Function Gate
Source
From the manufacturer's datasheet
Is it dead?
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.
Datasheetfor SN74LVC1G97DRL, opens in a new tab
SN74LVC1G98DRLprinted 1K5Logic gate, 6 pins, Texas InstrumentsLogic gate6 pinsTexas Instruments
Printed 1K5. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
What it is
Logic gate
Maker
Texas Instruments
Package
Not recorded
Pins
6
Details
Configurable Multiple-Function Gate
Source
From the manufacturer's datasheet
Is it dead?
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.
Datasheetfor SN74LVC1G98DRL, opens in a new tab
SN74LVC1G332DRLprinted 1K1Logic gate, 6 pins, Texas InstrumentsLogic gate6 pinsTexas Instruments
Printed 1K1. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
What it is
Logic gate
Maker
Texas Instruments
Package
Not recorded
Pins
6
Details
Single 3-Input Positive-OR Gate
Source
From the manufacturer's datasheet
Is it dead?
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.
Datasheetfor SN74LVC1G332DRL, opens in a new tab
SN74LVC2G04DRLprinted 1K7Logic gate, 6 pins, Texas InstrumentsLogic gate6 pinsTexas Instruments
Printed 1K7. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
What it is
Logic gate
Maker
Texas Instruments
Package
Not recorded
Pins
6
Details
Dual Inverter Gate
Source
From the manufacturer's datasheet
Is it dead?
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.
Datasheetfor SN74LVC2G04DRL, opens in a new tab
SN74LVC2G34DRLprinted 1K8Logic gate, 6 pins, Texas InstrumentsLogic gate6 pinsTexas Instruments
Printed 1K8. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
What it is
Logic gate
Maker
Texas Instruments
Package
Not recorded
Pins
6
Details
Dual Buffer Gate
Source
From the manufacturer's datasheet
Is it dead?
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.
Datasheetfor SN74LVC2G34DRL, opens in a new tab
TPD1E05U06DYAprinted 1KSESD protection diode, 2 pins, Texas InstrumentsESD protection diode2 pinsTexas Instruments
Printed 1KS. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
What it is
ESD protection diode
Maker
Texas Instruments
Package
Not recorded
Pins
2
Details
TPDxE05U06 1, 4, 6 Channel ESD Protection Device for Super-Speed (Up to 6 Gbps) Interface
Source
From the manufacturer's datasheet
Is it dead?
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:
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.
Datasheetfor TPD1E05U06DYA, opens in a new tab
TPD1E10B06DYAprinted 1KFESD protection diode, 2 pins, Texas InstrumentsESD protection diode2 pinsTexas Instruments
Printed 1KF. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
What it is
ESD protection diode
Maker
Texas Instruments
Package
Not recorded
Pins
2
Details
Single-Channel ESD Protection Diode
Source
From the manufacturer's datasheet
Is it dead?
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:
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.
Datasheetfor TPD1E10B06DYA, opens in a new tab

Open this in the search to correct a character or try another package.