SMD code search: identify a part by its marking

Not sure which one you have?

Answer up to 4 quick questions and these 50 parts are ranked, with a meter test that settles it. It works on a dead part too.

The only part printed SLT in our tables

SACB18

What it is: TVS diode
Maker: Littelfuse
Package: SMB
Pins: 2
Source: Published code list

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: , 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.

Datasheet

Was it this one?

Printed with a code easy to misread

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

GS1TA3000printed S1TSMARectifier, 2 pins, Good-ArkRectifierSMA2 pinsGood-Ark
Printed S1T on the part. Easy to misread as SLT. Check that character with a loupe before you order anything.
What it is
Rectifier
Maker
Good-Ark
Package
SMA
Pins
2
Details
Rectifier, 3000 V, 1 A
Source
Manufacturer 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
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 GS1TA3000, opens in a new tab
PJS6417printed S17SOT-23MOSFET, 3 pins, PanjitMOSFETSOT-233 pinsPanjit
Printed S17 on the part. Easy to misread as SLT. Check that character with a loupe before you order anything.
What it is
MOSFET
Maker
Panjit
Package
SOT-23
Pins
3
Source
Manufacturer datasheet
Is it dead?
Diode range, part lifted. Test drain to source first, then short gate to source and test again.
Working, it reads
One way between drain and source reads about 0.4 to 0.9 V, the body diode, and the other way open. The gate reads open to both other pins.
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.
No body diode at all: failed open.
On the board
the gate usually has a resistor to the source, which reads as that resistor and 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.
Datasheetfor PJS6417, opens in a new tab
S1T-HFprinted S1TSMARectifier, 2 pins, ComchipRectifierSMA2 pinsComchip
Printed S1T on the part. Easy to misread as SLT. Check that character with a loupe before you order anything.
What it is
Rectifier
Maker
Comchip
Package
SMA
Pins
2
Details
1300 V, 1 A rectifier
Source
Manufacturer 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
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 S1T-HF, opens in a new tab
SFM17printed S17SMARectifier, 2 pins, Formosa MicrosemiRectifierSMA2 pinsFormosa Microsemi
Printed S17 on the part. Easy to misread as SLT. Check that character with a loupe before you order anything.
What it is
Rectifier
Maker
Formosa Microsemi
Package
SMA
Pins
2
Details
Rectifier diode
Source
Manufacturer 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
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 SFM17, opens in a new tab
TPS70960DBVprinted SITSOT-23-5LDO regulator, 5 pins, Texas InstrumentsLDO regulatorSOT-23-55 pinsTexas Instruments
Printed SIT on the part. Easy to misread as SLT. Check that character with a loupe before you order anything.
What it is
LDO regulator
Maker
Texas Instruments
Package
SOT-23-5
Pins
5
Details
150-mA, 30-V, 1-µA IQ Voltage Regulators With Enable
Source
Manufacturer datasheet
Is it dead?
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.
Datasheetfor TPS70960DBV, opens in a new tab
ADG901BRMZprinted S1TMSOP-88 pins, Analog DevicesNot recordedMSOP-88 pinsAnalog Devices
Printed S1T on the part. Easy to misread as SLT. Check that character with a loupe before you order anything.
What it is
Not recorded
Maker
Analog Devices
Package
MSOP-8
Pins
8
Source
Published code list
Is it dead?
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.
AM5317Mprinted 5-17SOT-23LDO regulator, 3 pins, Xiang Shuo ElectronicsLDO regulatorSOT-233 pinsXiang Shuo Electronics
Printed 5-17 on the part. Easy to misread as SLT. Check that character with a loupe before you order anything.
What it is
LDO regulator
Maker
Xiang Shuo Electronics
Package
SOT-23
Pins
3
Details
Linear voltage regulator IC: LDO, 1.7V±2%, 500mA
Source
Published code list
Is it dead?
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.
AM5317Pprinted 5-17SOT-89LDO regulator, 3 pins, Xiang Shuo ElectronicsLDO regulatorSOT-893 pinsXiang Shuo Electronics
Printed 5-17 on the part. Easy to misread as SLT. Check that character with a loupe before you order anything.
What it is
LDO regulator
Maker
Xiang Shuo Electronics
Package
SOT-89
Pins
3
Details
Linear voltage regulator IC: LDO, 1.7V±2%, 500mA
Source
Published code list
Is it dead?
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.
BS817printed S17SOT-233 pins, IntermetallNot recordedSOT-233 pinsIntermetall
Printed S17 on the part. Easy to misread as SLT. Check that character with a loupe before you order anything.
What it is
Not recorded
Maker
Intermetall
Package
SOT-23
Pins
3
Source
Published code list
Is it dead?
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.
CHT817WPT-Sprinted S17SOT-323NPN transistor, 3 pins, Chenmko EnterpriseNPN transistorSOT-3233 pinsChenmko Enterprise
Printed S17 on the part. Easy to misread as SLT. Check that character with a loupe before you order anything.
What it is
NPN transistor
Maker
Chenmko Enterprise
Package
SOT-323
Pins
3
Details
NPN transistor: AF, Sw, 45V, 500mA, B=250..600, 170MHz
Source
Published code list
Is it dead?
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.
FMMT6517printed 517SOT-233 pins, Diodes IncorporatedNot recordedSOT-233 pinsDiodes Incorporated
Printed 517 on the part. Easy to misread as SLT. Check that character with a loupe before you order anything.
What it is
Not recorded
Maker
Diodes Incorporated
Package
SOT-23
Pins
3
Details
Si-npn: Vid, 350/350V, 500mA, 330mW, B=30..200, >50MHz
Source
Published code list
Is it dead?
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.
FMMT6517TAprinted 517SOT-233 pins, Diodes IncorporatedNot recordedSOT-233 pinsDiodes Incorporated
Printed 517 on the part. Easy to misread as SLT. Check that character with a loupe before you order anything.
What it is
Not recorded
Maker
Diodes Incorporated
Package
SOT-23
Pins
3
Details
NPN high voltage transistor
Source
Published code list
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
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.
IXD2111A171MRprinted 517SOT-23DC-DC converter, 3 pins, IXYSDC-DC converterSOT-233 pinsIXYS
Printed 517 on the part. Easy to misread as SLT. Check that character with a loupe before you order anything.
What it is
DC-DC converter
Maker
IXYS
Package
SOT-23
Pins
3
Details
DC/DC voltage converter IC: PFM st-up, 100kHz, 1.7V±2.5%, 400mA
Source
Published code list
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.
IXD2111A171PRprinted 517SOT-89DC-DC converter, 3 pins, IXYSDC-DC converterSOT-893 pinsIXYS
Printed 517 on the part. Easy to misread as SLT. Check that character with a loupe before you order anything.
What it is
DC-DC converter
Maker
IXYS
Package
SOT-89
Pins
3
Details
DC/DC voltage converter IC: PFM st-up, 100kHz, 1.7V±2.5%, 400mA
Source
Published code list
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.
IXD2111C171MRprinted 517SOT-23-5DC-DC converter, 5 pins, IXYSDC-DC converterSOT-23-55 pinsIXYS
Printed 517 on the part. Easy to misread as SLT. Check that character with a loupe before you order anything.
What it is
DC-DC converter
Maker
IXYS
Package
SOT-23-5
Pins
5
Details
DC/DC voltage converter IC: PFM st-up, 100kHz, 1.7V±2.5%, 400mA, +CE
Source
Published code list
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.
IXD3236A37DER-Gprinted 5L7USP-6CDC-DC converter, 6 pins, IXYSDC-DC converterUSP-6C6 pinsIXYS
Printed 5L7 on the part. Easy to misread as SLT. Check that character with a loupe before you order anything.
What it is
DC-DC converter
Maker
IXYS
Package
USP-6C
Pins
6
Details
DC/DC voltage converter IC: PWM/PFM, st-dwn, 3.7V±2%, 600mA, 3MHz, Vin>2V, LSST
Source
Published code list
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.
IXD3236A37DMR-Gprinted 5L7SOT-23-5DC-DC converter, 5 pins, IXYSDC-DC converterSOT-23-55 pinsIXYS
Printed 5L7 on the part. Easy to misread as SLT. Check that character with a loupe before you order anything.
What it is
DC-DC converter
Maker
IXYS
Package
SOT-23-5
Pins
5
Details
DC/DC voltage converter IC: PWM/PFM, st-dwn, 3.7V±2%, 600mA, 3MHz, Vin>2V, LSST
Source
Published code list
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.
IXD5127C32EMRprinted 5LTSOT-23-5Voltage supervisor, 5 pins, IXYSVoltage supervisorSOT-23-55 pinsIXYS
Printed 5LT on the part. Easy to misread as SLT. Check that character with a loupe before you order anything.
What it is
Voltage supervisor
Maker
IXYS
Package
SOT-23-5
Pins
5
Details
Voltage detector IC: 3.2V±0.8%, -Reset PPO, -MR, Rdt=800ms
Source
Published code list
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.
KIC77D17T2printed S17SOT-23Voltage supervisor, 3 pins, KECVoltage supervisorSOT-233 pinsKEC
Printed S17 on the part. Easy to misread as SLT. Check that character with a loupe before you order anything.
What it is
Voltage supervisor
Maker
KEC
Package
SOT-23
Pins
3
Details
Voltage detector IC: 1.7V±1%, -Reset ODO, Rdt=200ms
Source
Published code list
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.
LD6919GDAW-17printed S17WSONLDO regulator, LeadtrendLDO regulatorWSONNot recordedLeadtrend
Printed S17 on the part. Easy to misread as SLT. Check that character with a loupe before you order anything.
What it is
LDO regulator
Maker
Leadtrend
Package
WSON
Pins
Not recorded
Details
Linear voltage regulator IC: LDO, Ultra-LN, Soft start, 1.7V±2%, 500mA, +CE
Source
Published code list
Is it dead?
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.
MMBZ5251BTWprinted 51TSOT-363Zener diode, 6 pins, PanjitZener diodeSOT-3636 pinsPanjit
Printed 51T on the part. Easy to misread as SLT. Check that character with a loupe before you order anything.
What it is
Zener diode
Maker
Panjit
Package
SOT-363
Pins
6
Source
An older or alternative marking, from a published code list
Is it dead?
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.
Datasheetfor MMBZ5251BTW, opens in a new tab
R1114N171Bprinted 517SOT-23-55 pins, Nisshinbo Micro DevicesNot recordedSOT-23-55 pinsNisshinbo Micro Devices
Printed 517 on the part. Easy to misread as SLT. Check that character with a loupe before you order anything.
What it is
Not recorded
Maker
Nisshinbo Micro Devices
Package
SOT-23-5
Pins
5
Details
VR-IC: LDO, LN, -CE, 1,7V±2%, 150mA
Source
Published code list
Is it dead?
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.
R1162N171Bprinted S17SOT-23-55 pins, RicohNot recordedSOT-23-55 pinsRicoh
Printed S17 on the part. Easy to misread as SLT. Check that character with a loupe before you order anything.
What it is
Not recorded
Maker
Ricoh
Package
SOT-23-5
Pins
5
Details
VR-IC: LDO, CE, 1.7V±2%, 150mA
Source
Published code list
Is it dead?
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.
R1191N117Bprinted 517SOT-23-5LDO regulator, 5 pins, RicohLDO regulatorSOT-23-55 pinsRicoh
Printed 517 on the part. Easy to misread as SLT. Check that character with a loupe before you order anything.
What it is
LDO regulator
Maker
Ricoh
Package
SOT-23-5
Pins
5
Details
Linear voltage regulator IC: LDO, 11.7V±1.5%, 300mA, +CE, ECO
Source
Published code list
Is it dead?
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.
R3134N26ECprinted S1TSOT-23-5Voltage supervisor, 5 pins, RicohVoltage supervisorSOT-23-55 pinsRicoh
Printed S1T on the part. Easy to misread as SLT. Check that character with a loupe before you order anything.
What it is
Voltage supervisor
Maker
Ricoh
Package
SOT-23-5
Pins
5
Details
Voltage detector IC: 2.6V±1.8%, -Reset PPO, -MR
Source
Published code list
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.
RP100N121D5printed 51TSOT-23-5LDO regulator, 5 pins, RicohLDO regulatorSOT-23-55 pinsRicoh
Printed 51T on the part. Easy to misread as SLT. Check that character with a loupe before you order anything.
What it is
LDO regulator
Maker
Ricoh
Package
SOT-23-5
Pins
5
Details
Linear voltage regulator IC: LDO, LN, 1.25V±0.8%, 200mA, +CE, CL
Source
Published code list
Is it dead?
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.
RP202N171Bprinted S17SOT-23-5LDO regulator, 5 pins, RicohLDO regulatorSOT-23-55 pinsRicoh
Printed S17 on the part. Easy to misread as SLT. Check that character with a loupe before you order anything.
What it is
LDO regulator
Maker
Ricoh
Package
SOT-23-5
Pins
5
Details
Linear voltage regulator IC: LDO, 1.7V±1%, 200mA, +CE
Source
Published code list
Is it dead?
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.
S5KP17printed 517D2PAKTVS diode, 3 pins, EIC SemiconductorTVS diodeD2PAK3 pinsEIC Semiconductor
Printed 517 on the part. Easy to misread as SLT. Check that character with a loupe before you order anything.
What it is
TVS diode
Maker
EIC Semiconductor
Package
D2PAK
Pins
3
Details
Transient voltage supressor: Vbr=18.9..23.1V, Vrwm=17V, 164A, 5000W(1ms)
Source
Published code list
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
, 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.
SGM2122-PYN6Gprinted S17SOT-23-6LDO regulator, 6 pins, SG MicroLDO regulatorSOT-23-66 pinsSG Micro
Printed S17 on the part. Easy to misread as SLT. Check that character with a loupe before you order anything.
What it is
LDO regulator
Maker
SG Micro
Package
SOT-23-6
Pins
6
Details
Linear voltage regulator IC: LDO, Dual out, Vout1/Vout2=1.5V/2.8V±2%, 250mA, +CE
Source
Published code list
Is it dead?
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.
SN74AUP1G08QDCKprinted SITSOT-3535 pins, Texas InstrumentsNot recordedSOT-3535 pinsTexas Instruments
Printed SIT on the part. Easy to misread as SLT. Check that character with a loupe before you order anything.
What it is
Not recorded
Maker
Texas Instruments
Package
SOT-353
Pins
5
Details
CMOS logic IC: 2-input AND gate
Source
Published code list
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.
UM1450S-41printed 5LTSOT-23LDO regulator, 3 pins, Union SemiconductorLDO regulatorSOT-233 pinsUnion Semiconductor
Printed 5LT on the part. Easy to misread as SLT. Check that character with a loupe before you order anything.
What it is
LDO regulator
Maker
Union Semiconductor
Package
SOT-23
Pins
3
Details
Linear voltage regulator IC: LDO, 4.1V±3%, 250mA
Source
Published code list
Is it dead?
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.
UM1550S-47printed 5L7SOT-23LDO regulator, 3 pins, Union SemiconductorLDO regulatorSOT-233 pinsUnion Semiconductor
Printed 5L7 on the part. Easy to misread as SLT. Check that character with a loupe before you order anything.
What it is
LDO regulator
Maker
Union Semiconductor
Package
SOT-23
Pins
3
Details
Linear voltage regulator IC: LDO, 4.7V±2%, 200mA
Source
Published code list
Is it dead?
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.
XC6127C32EMRprinted 5LTSOT-23-5Voltage supervisor, 5 pins, TorexVoltage supervisorSOT-23-55 pinsTorex
Printed 5LT on the part. Easy to misread as SLT. Check that character with a loupe before you order anything.
What it is
Voltage supervisor
Maker
Torex
Package
SOT-23-5
Pins
5
Details
Voltage detector IC: 3.2V±0.8%, -Reset PPO, -MR, Rdt=800ms
Source
Published code list
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.
XC9111A171MRprinted 517SOT-23DC-DC converter, 3 pins, TorexDC-DC converterSOT-233 pinsTorex
Printed 517 on the part. Easy to misread as SLT. Check that character with a loupe before you order anything.
What it is
DC-DC converter
Maker
Torex
Package
SOT-23
Pins
3
Details
DC/DC voltage converter IC: PFM st-up, 100kHz, 1.7V±2.5%, 400mA
Source
Published code list
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.
XC9111A171PRprinted 517SOT-89DC-DC converter, 3 pins, TorexDC-DC converterSOT-893 pinsTorex
Printed 517 on the part. Easy to misread as SLT. Check that character with a loupe before you order anything.
What it is
DC-DC converter
Maker
Torex
Package
SOT-89
Pins
3
Details
DC/DC voltage converter IC: PFM st-up, 100kHz, 1.7V±2.5%, 400mA
Source
Published code list
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.
XC9111C171MRprinted 517SOT-23-5DC-DC converter, 5 pins, TorexDC-DC converterSOT-23-55 pinsTorex
Printed 517 on the part. Easy to misread as SLT. Check that character with a loupe before you order anything.
What it is
DC-DC converter
Maker
Torex
Package
SOT-23-5
Pins
5
Details
DC/DC voltage converter IC: PFM st-up, 100kHz, 1.7V±2.5%, 400mA, +CE
Source
Published code list
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.
XC9148A45CER-Gprinted S17USP-6CDC-DC converter, 6 pins, TorexDC-DC converterUSP-6C6 pinsTorex
Printed S17 on the part. Easy to misread as SLT. Check that character with a loupe before you order anything.
What it is
DC-DC converter
Maker
Torex
Package
USP-6C
Pins
6
Details
DC/DC voltage converter IC: PWM/PFM st-up, 1.2MHz, 4.5V±2%, 1.4A, CrL, CL, +CE
Source
Published code list
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.
12 more parts have no package on record
- ESD5L5.0printed 51TESD protection diode, Formosa MicrosemiESD protection diodeNot recordedNot recordedFormosa Microsemi
  Printed 51T on the part. Easy to misread as SLT. Check that character with a loupe before you order anything.
  What it is
  ESD protection diode
  Maker
  Formosa Microsemi
  Package
  Not recorded
  Pins
  Not recorded
  Source
  Manufacturer 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
  , 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 ESD5L5.0, opens in a new tab
- GSS17Eprinted S17Schottky diode, Good-ArkSchottky diodeNot recordedNot recordedGood-Ark
  Printed S17 on the part. Easy to misread as SLT. Check that character with a loupe before you order anything.
  What it is
  Schottky diode
  Maker
  Good-Ark
  Package
  Not recorded
  Pins
  Not recorded
  Details
  Schottky diode, 70 V, 1 A
  Source
  Manufacturer datasheet
  Is it dead?
  Diode range, part lifted or one leg off the pad. Red probe on the anode.
  Working, it reads
  About 0.15 to 0.45 V anode to cathode, roughly half a silicon diode, and open the other way.
  Dead, it reads
  The same reading both ways round, near 0 V with a continuous beep or the same middling value: shorted.
  A reading the wrong way round as well: leaky.
  Open both ways: failed open.
  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 large Schottky can read about 0.1 V forward and beep like a short, and leaks a little the wrong way when good, more when warm. It is shorted only if it reads the same both ways. Measure it cold, beside an identical cold one.
  A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.
  Datasheetfor GSS17E, opens in a new tab
- SDT517printed 517MOSFET, SeCoSMOSFETNot recordedNot recordedSeCoS
  Printed 517 on the part. Easy to misread as SLT. Check that character with a loupe before you order anything.
  What it is
  MOSFET
  Maker
  SeCoS
  Package
  Not recorded
  Pins
  Not recorded
  Source
  Manufacturer datasheet
  Is it dead?
  Diode range, part lifted. Test drain to source first, then short gate to source and test again.
  Working, it reads
  One way between drain and source reads about 0.4 to 0.9 V, the body diode, and the other way open. The gate reads open to both other pins.
  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.
  No body diode at all: failed open.
  On the board
  the gate usually has a resistor to the source, which reads as that resistor and 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.
  Datasheetfor SDT517, opens in a new tab
- SFM17-Lprinted S17Rectifier, Formosa MicrosemiRectifierNot recordedNot recordedFormosa Microsemi
  Printed S17 on the part. Easy to misread as SLT. Check that character with a loupe before you order anything.
  What it is
  Rectifier
  Maker
  Formosa Microsemi
  Package
  Not recorded
  Pins
  Not recorded
  Details
  Rectifier diode
  Source
  Manufacturer 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
  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 SFM17-L, opens in a new tab
- SFM17-SFprinted S17Rectifier, Formosa MicrosemiRectifierNot recordedNot recordedFormosa Microsemi
  Printed S17 on the part. Easy to misread as SLT. Check that character with a loupe before you order anything.
  What it is
  Rectifier
  Maker
  Formosa Microsemi
  Package
  Not recorded
  Pins
  Not recorded
  Details
  Rectifier diode
  Source
  Manufacturer 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
  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 SFM17-SF, opens in a new tab
- SFM17-SF-Q1printed S17Rectifier, Formosa MicrosemiRectifierNot recordedNot recordedFormosa Microsemi
  Printed S17 on the part. Easy to misread as SLT. Check that character with a loupe before you order anything.
  What it is
  Rectifier
  Maker
  Formosa Microsemi
  Package
  Not recorded
  Pins
  Not recorded
  Details
  Rectifier diode
  Source
  Manufacturer 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
  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 SFM17-SF-Q1, opens in a new tab
- TPQ051007-DFORprinted 5176 pins, 3PEAKNot recordedNot recorded6 pins3PEAK
  Printed 517 on the part. Easy to misread as SLT. Check that character with a loupe before you order anything.
  What it is
  Not recorded
  Maker
  3PEAK
  Package
  Not recorded
  Pins
  6
  Details
  0.9-V to 5.5-V VIN, 600-mA Synchronous Step-up Regulator
  Source
  Manufacturer datasheet
  Is it dead?
  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.
  Datasheetfor TPQ051007-DFOR, opens in a new tab
- ADG901BCPZ-REEL7printed S1T8 pins, Analog DevicesNot recordedNot recorded8 pinsAnalog Devices
  Printed S1T on the part. Easy to misread as SLT. Check that character with a loupe before you order anything.
  What it is
  Not recorded
  Maker
  Analog Devices
  Package
  Not recorded
  Pins
  8
  Source
  Published code list
  Is it dead?
  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.
- IXD3236A37D0R-Gprinted 5L7DC-DC converter, IXYSDC-DC converterNot recordedNot recordedIXYS
  Printed 5L7 on the part. Easy to misread as SLT. Check that character with a loupe before you order anything.
  What it is
  DC-DC converter
  Maker
  IXYS
  Package
  Not recorded
  Pins
  Not recorded
  Details
  DC/DC voltage converter IC: PWM/PFM, st-dwn, 3.7V±2%, 600mA, 3MHz, Vin>2V, LSST
  Source
  Published code list
  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.
- IXD3236A37D4R-Gprinted 5L7DC-DC converter, IXYSDC-DC converterNot recordedNot recordedIXYS
  Printed 5L7 on the part. Easy to misread as SLT. Check that character with a loupe before you order anything.
  What it is
  DC-DC converter
  Maker
  IXYS
  Package
  Not recorded
  Pins
  Not recorded
  Details
  DC/DC voltage converter IC: PWM/PFM, st-dwn, 3.7V±2%, 600mA, 3MHz, Vin>2V, LSST
  Source
  Published code list
  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.
- IXD9206A373AR-Gprinted 5L7DC-DC converter, ZilogDC-DC converterNot recordedNot recordedZilog
  Printed 5L7 on the part. Easy to misread as SLT. Check that character with a loupe before you order anything.
  What it is
  DC-DC converter
  Maker
  Zilog
  Package
  Not recorded
  Pins
  Not recorded
  Details
  DC/DC voltage converter IC: PWM/PFM st-dwn, 3MHz, 3.7V±2%, 600mA
  Source
  Published code list
  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.
- KIC77D17M2printed S17Voltage supervisor, KECVoltage supervisorNot recordedNot recordedKEC
  Printed S17 on the part. Easy to misread as SLT. Check that character with a loupe before you order anything.
  What it is
  Voltage supervisor
  Maker
  KEC
  Package
  Not recorded
  Pins
  Not recorded
  Details
  Voltage detector IC: 1.7V±1%, -Reset ODO, Rdt=200ms
  Source
  Published code list
  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.

8 more parts are not listed here. Type more of the code to narrow the list.

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One code, several parts

Marking codes are not unique. In the standard code book, 6H on a SOT-23 is an NPN transistor, a varicap, an N-channel JFET, two digital transistors, a 3.6 V voltage detector: six parts from five makers. So a search shows the parts we hold under that code and under codes easily misread as it, with only the columns that tell them apart.

6Hon a SOT-23, in the code book

NPN transistor
Varicap
N-channel JFET
Digital transistor ×2
3.6 V voltage detector

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SACB18

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Printed with a code easy to misread

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One code, several parts

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