SMD code search: identify a part by its marking

6 parts are printed SCB

Not sure which one you have?

Answer up to 4 quick questions and these 6 parts are ranked, with a meter test that settles it. It works on a dead part too.

WS36DF-B-ATSOD-882ESD protection diode, 2 pins, WayonESD protection diodeSOD-8822 pinsWayon
What it is
ESD protection diode
Maker
Wayon
Package
SOD-882
Pins
2
Source
Manufacturer datasheet
Is it dead?
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 WS36DF-B-AT, opens in a new tab
WS36DF-BHSOD-882ESD protection diode, 2 pins, WayonESD protection diodeSOD-8822 pinsWayon
What it is
ESD protection diode
Maker
Wayon
Package
SOD-882
Pins
2
Source
Manufacturer datasheet
Is it dead?
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 WS36DF-BH, opens in a new tab
FJX597JBSOT-3233 pins, Fairchild SemiconductorNot recordedSOT-3233 pinsFairchild Semiconductor
What it is
Not recorded
Maker
Fairchild Semiconductor
Package
SOT-323
Pins
3
Details
FET n-type: Cap. microphone, 20V, 10mA, 100mW, Idss=150..240uA
Source
Published code list
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.
LM810M3-4.00SOT-23Voltage supervisor, 3 pins, National SemiconductorVoltage supervisorSOT-233 pinsNational Semiconductor
What it is
Voltage supervisor
Maker
National Semiconductor
Package
SOT-23
Pins
3
Details
Voltage detector IC: 4.0V±1.5%, +Reset PPO
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.
XC9148G29CER-GUSP-6CDC-DC converter, 6 pins, TorexDC-DC converterUSP-6C6 pinsTorex
What it is
DC-DC converter
Maker
Torex
Package
USP-6C
Pins
6
Details
DC/DC voltage converter IC: PWM/PFM st-up, 1.2MHz, 2.9V±2%, 1.4A, ULVO, 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.
XC9148G29CPR-GSOT-89-5DC-DC converter, 5 pins, TorexDC-DC converterSOT-89-55 pinsTorex
What it is
DC-DC converter
Maker
Torex
Package
SOT-89-5
Pins
5
Details
DC/DC voltage converter IC: PW M/PFM step-up, 1.2MHz, 2.9V±2%, 1.4A, ULVO, 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.

98 more parts are printed with a code easy to misread as SCB

Printed with a code easy to misread

One character differs, and it is one that is easy to confuse under a lamp. The odd one out is marked on each.

APL3556Bprinted 56BSOT-23-5Load switch, 5 pins, AnpecLoad switchSOT-23-55 pinsAnpec
Printed 56B on the part. Easy to misread as SCB. Check that character with a loupe before you order anything.
What it is
Load switch
Maker
Anpec
Package
SOT-23-5
Pins
5
Details
Adjustable Current Limit Power Distribution Switches
Source
Manufacturer datasheet
Is it dead?
Voltage, board powered, black probe on ground.
Working, it reads
Switched on, the output pin sits at the input voltage. Switched off, it sits near 0 V.
Dead, it reads
Output at the input voltage while switched off: the pass element has shorted.
Input present and switched on, no output: failed open, or shut down into a shorted load. Power off and measure output to ground.
On the board:
An output near 0 Ω to ground is usually the load. Lift the output pin to see which.
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 pinout and whether the enable is active high or low differ between parts. The datasheet gives both.
A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.
Datasheetfor APL3556B, opens in a new tab
BC856Bprinted 56BSOT-23PNP transistor, 3 pins, PanjitPNP transistorSOT-233 pinsPanjit
Printed 56B on the part. Easy to misread as SCB. Check that character with a loupe before you order anything.
What it is
PNP transistor
Maker
Panjit
Package
SOT-23
Pins
3
Details
-80 V PNP small-signal transistor, gain group B
Source
Manufacturer datasheet
Is it dead?
Diode range, part lifted or its base leg off the pad.
Working, it reads
Black probe on the base reads about 0.6 to 0.75 V to the emitter and to the collector, and open the other way round. Collector to emitter reads open both ways.
Dead, it reads
Collector to emitter the same both ways, near 0 V with a continuous beep: shorted. The commonest failure.
The base the same both ways to another pin, near 0 V or a middling value: a shorted junction.
Only one junction reads, or none: a junction has failed open. It then looks like a diode.
A reading the wrong way round, where it should be open: leaky.
On the board
this is a first look only: the meter reads every path between those pins, and a short can be a neighbour. Lift one leg before you condemn it.
Compare:
If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
Watch for:
A pair of diodes with a common pin reads just like a transistor, and some transistors carry a built-in diode or resistor. The datasheet says which.
A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.
Datasheetfor BC856B, opens in a new tab
BC856B-AUprinted 56BSOT-23Transistor, 3 pins, PanjitTransistorSOT-233 pinsPanjit
Printed 56B on the part. Easy to misread as SCB. Check that character with a loupe before you order anything.
What it is
Transistor
Maker
Panjit
Package
SOT-23
Pins
3
Details
Bipolar transistor
Source
Manufacturer 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
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 BC856B-AU, opens in a new tab
BC856BDW-Q1printed 56BSOT-363Dual PNP transistor, 6 pins, Formosa MicrosemiDual PNP transistorSOT-3636 pinsFormosa Microsemi
Printed 56B on the part. Easy to misread as SCB. Check that character with a loupe before you order anything.
What it is
Dual PNP transistor
Maker
Formosa Microsemi
Package
SOT-363
Pins
6
Source
Manufacturer 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
Black probe on the base reads about 0.6 to 0.75 V to the emitter and to the collector, and open the other way round. Collector to emitter reads open both ways.
Dead, it reads
Collector to emitter the same both ways, near 0 V with a continuous beep: shorted. The commonest failure.
The base the same both ways to another pin, near 0 V or a middling value: a shorted junction.
Only one junction reads, or none: a junction has failed open. It then looks like a diode.
A reading the wrong way round, where it should be open: leaky.
On the board
this is a first look only: the meter reads every path between those pins, and a short can be a neighbour. Lift one leg before you condemn it.
Compare:
If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
Watch for:
A pair of diodes with a common pin reads just like a transistor, and some transistors carry a built-in diode or resistor. The datasheet says which.
A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.
Datasheetfor BC856BDW-Q1, opens in a new tab
BC856BWprinted 56BSOT-323Transistor, 3 pins, PanjitTransistorSOT-3233 pinsPanjit
Printed 56B on the part. Easy to misread as SCB. Check that character with a loupe before you order anything.
What it is
Transistor
Maker
Panjit
Package
SOT-323
Pins
3
Details
SMD General Purpose PNP Transistors
Source
Manufacturer 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
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 BC856BW, opens in a new tab
BC856BW-AUprinted 56BSOT-323Transistor, 3 pins, PanjitTransistorSOT-3233 pinsPanjit
Printed 56B on the part. Easy to misread as SCB. Check that character with a loupe before you order anything.
What it is
Transistor
Maker
Panjit
Package
SOT-323
Pins
3
Details
Bipolar transistor
Source
Manufacturer 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
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 BC856BW-AU, opens in a new tab
LBC817-25DPMT1Gprinted 56BSOT-23-6Transistor, 6 pins, LRCTransistorSOT-23-66 pinsLRC
Printed 56B on the part. Easy to misread as SCB. Check that character with a loupe before you order anything.
What it is
Transistor
Maker
LRC
Package
SOT-23-6
Pins
6
Details
Bipolar transistor, P+N, IC 500 mA, VCEO 45 V
Source
Manufacturer 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
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 LBC817-25DPMT1G, opens in a new tab
PDZV5.6Bprinted 5.6BSOD-128Zener diode, 2 pins, ROHMZener diodeSOD-1282 pinsROHM
Printed 5.6B on the part. Easy to misread as SCB. Check that character with a loupe before you order anything.
What it is
Zener diode
Maker
ROHM
Package
SOD-128
Pins
2
Source
Manufacturer datasheet
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 PDZV5.6B, opens in a new tab
PDZVTF5.6Bprinted 5.6BSOD-128Zener diode, 2 pins, ROHMZener diodeSOD-1282 pinsROHM
Printed 5.6B on the part. Easy to misread as SCB. Check that character with a loupe before you order anything.
What it is
Zener diode
Maker
ROHM
Package
SOD-128
Pins
2
Details
Zener Diode (AEC-Q101 qualified)
Source
Manufacturer datasheet
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 PDZVTF5.6B, opens in a new tab
PLCDA05printed SGBSOIC-8ESD protection diode, 8 pins, ProTek DevicesESD protection diodeSOIC-88 pinsProTek Devices
Printed SGB on the part. Easy to misread as SCB. Check that character with a loupe before you order anything.
What it is
ESD protection diode
Maker
ProTek Devices
Package
SOIC-8
Pins
8
Details
500 Watt Multi-Line Ultra Low Capacitance TVS Array
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 PLCDA05, opens in a new tab
PTZ5.6Bprinted 5.6BMELFZener diode, 2 pins, ROHMZener diodeMELF2 pinsROHM
Printed 5.6B on the part. Easy to misread as SCB. Check that character with a loupe before you order anything.
What it is
Zener diode
Maker
ROHM
Package
MELF
Pins
2
Source
Manufacturer datasheet
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 PTZ5.6B, opens in a new tab
S-LBC817-25DPMT1Gprinted 56BSOT-23-6Transistor, 6 pins, LRCTransistorSOT-23-66 pinsLRC
Printed 56B on the part. Easy to misread as SCB. Check that character with a loupe before you order anything.
What it is
Transistor
Maker
LRC
Package
SOT-23-6
Pins
6
Details
Bipolar transistor, P+N, IC 500 mA, VCEO 45 V
Source
Manufacturer 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
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 S-LBC817-25DPMT1G, opens in a new tab
S6BCprinted S6BSMCRectifier, 2 pins, YFWRectifierSMC2 pinsYFW
Printed S6B on the part. Easy to misread as SCB. Check that character with a loupe before you order anything.
What it is
Rectifier
Maker
YFW
Package
SMC
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 S6BC, opens in a new tab
1SMA5956Bprinted 56BSMAZener diode, 2 pins, RectronZener diodeSMA2 pinsRectron
Printed 56B on the part. Easy to misread as SCB. Check that character with a loupe before you order anything.
What it is
Zener diode
Maker
Rectron
Package
SMA
Pins
2
Source
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 1SMA5956B, opens in a new tab
1SMB3EZ56printed 56BSMBZener diode, 2 pins, PanjitZener diodeSMB2 pinsPanjit
Printed 56B on the part. Easy to misread as SCB. Check that character with a loupe before you order anything.
What it is
Zener diode
Maker
Panjit
Package
SMB
Pins
2
Details
Z-diode: 56V±5%, 3W
Source
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.
ADG721BRMprinted S6BMSOP-88 pins, Analog DevicesNot recordedMSOP-88 pinsAnalog Devices
Printed S6B on the part. Easy to misread as SCB. 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.
ADG721BRMZprinted S6BMSOP-88 pins, Analog DevicesNot recordedMSOP-88 pinsAnalog Devices
Printed S6B on the part. Easy to misread as SCB. 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.
AM5368Mprinted 5-68SOT-23LDO regulator, 3 pins, Xiang Shuo ElectronicsLDO regulatorSOT-233 pinsXiang Shuo Electronics
Printed 5-68 on the part. Easy to misread as SCB. 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, 6.8V±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.
AM5368Pprinted 5-68SOT-89LDO regulator, 3 pins, Xiang Shuo ElectronicsLDO regulatorSOT-893 pinsXiang Shuo Electronics
Printed 5-68 on the part. Easy to misread as SCB. 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, 6.8V±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.
ECL112139B1Rprinted S68SOT-23LDO regulator, 3 pins, E-CMOSLDO regulatorSOT-233 pinsE-CMOS
Printed S68 on the part. Easy to misread as SCB. Check that character with a loupe before you order anything.
What it is
LDO regulator
Maker
E-CMOS
Package
SOT-23
Pins
3
Details
Linear voltage regulator IC: LDO, 3.9V±2%, 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.
ECL112142B1Rprinted S6BSOT-23LDO regulator, 3 pins, E-CMOSLDO regulatorSOT-233 pinsE-CMOS
Printed S6B on the part. Easy to misread as SCB. Check that character with a loupe before you order anything.
What it is
LDO regulator
Maker
E-CMOS
Package
SOT-23
Pins
3
Details
Linear voltage regulator IC: LDO, 4.2V±2%, 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.
FT533Gbprinted 5GbSOT-23-5LDO regulator, 5 pins, Fremont Micro DevicesLDO regulatorSOT-23-55 pinsFremont Micro Devices
Printed 5Gb on the part. Easy to misread as SCB. Check that character with a loupe before you order anything.
What it is
LDO regulator
Maker
Fremont Micro Devices
Package
SOT-23-5
Pins
5
Details
Linear voltage regulator IC: LDO, 2.8V±2%, 700mA, +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.
IXD2111A681MRprinted 568SOT-23DC-DC converter, 3 pins, IXYSDC-DC converterSOT-233 pinsIXYS
Printed 568 on the part. Easy to misread as SCB. 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, 6.8V±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.
IXD2111A681PRprinted 568SOT-89DC-DC converter, 3 pins, IXYSDC-DC converterSOT-893 pinsIXYS
Printed 568 on the part. Easy to misread as SCB. 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, 6.8V±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.
IXD2111C681MRprinted 568SOT-23-5DC-DC converter, 5 pins, IXYSDC-DC converterSOT-23-55 pinsIXYS
Printed 568 on the part. Easy to misread as SCB. 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, 6.8V±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.
IXD3236A2BCER-Gprinted 5CBUSP-6CDC-DC converter, 6 pins, IXYSDC-DC converterUSP-6C6 pinsIXYS
Printed 5CB on the part. Easy to misread as SCB. 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, 2.15V±2%, 600mA, 1.2MHz, 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.
IXD3236A2BCMR-Gprinted 5CBSOT-23-5DC-DC converter, 5 pins, IXYSDC-DC converterSOT-23-55 pinsIXYS
Printed 5CB on the part. Easy to misread as SCB. 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, 2.15V±2%, 600mA, 1.2MHz, 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.
IXD3236A28CER-Gprinted 5C8USP-6CDC-DC converter, 6 pins, IXYSDC-DC converterUSP-6C6 pinsIXYS
Printed 5C8 on the part. Easy to misread as SCB. 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, 2.8V±2%, 600mA, 1.2MHz, 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.
IXD3236A28CMR-Gprinted 5C8SOT-23-5DC-DC converter, 5 pins, IXYSDC-DC converterSOT-23-55 pinsIXYS
Printed 5C8 on the part. Easy to misread as SCB. 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, 2.8V±2%, 600mA, 1.2MHz, 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.
IXD5127C19BMRprinted 5CBSOT-23-5Voltage supervisor, 5 pins, IXYSVoltage supervisorSOT-23-55 pinsIXYS
Printed 5CB on the part. Easy to misread as SCB. 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: 1.9V±0.8%, -Reset PPO, -MR, Rdt=100ms
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.
LM809M3-4.00printed S6BSOT-23Voltage supervisor, 3 pins, National SemiconductorVoltage supervisorSOT-233 pinsNational Semiconductor
Printed S6B on the part. Easy to misread as SCB. Check that character with a loupe before you order anything.
What it is
Voltage supervisor
Maker
National Semiconductor
Package
SOT-23
Pins
3
Details
Voltage detector IC: 4.0V±1.5%, -Reset PPO
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.
LN1130P392MRprinted S68SOT-23LDO regulator, 3 pins, Shanghai Natlinear ElectronicsLDO regulatorSOT-233 pinsShanghai Natlinear Electronics
Printed S68 on the part. Easy to misread as SCB. Check that character with a loupe before you order anything.
What it is
LDO regulator
Maker
Shanghai Natlinear Electronics
Package
SOT-23
Pins
3
Details
Linear voltage regulator IC: LDO, 3.9V±2%, 300mA
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.
LN1130P392PRprinted S68SOT-89LDO regulator, 3 pins, Shanghai Natlinear ElectronicsLDO regulatorSOT-893 pinsShanghai Natlinear Electronics
Printed S68 on the part. Easy to misread as SCB. Check that character with a loupe before you order anything.
What it is
LDO regulator
Maker
Shanghai Natlinear Electronics
Package
SOT-89
Pins
3
Details
Linear voltage regulator IC: LDO, 3.9V±2%, 300mA
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.
LN1130P422MRprinted S6BSOT-23LDO regulator, 3 pins, Shanghai Natlinear ElectronicsLDO regulatorSOT-233 pinsShanghai Natlinear Electronics
Printed S6B on the part. Easy to misread as SCB. Check that character with a loupe before you order anything.
What it is
LDO regulator
Maker
Shanghai Natlinear Electronics
Package
SOT-23
Pins
3
Details
Linear voltage regulator IC: LDO, 4.2V±2%, 300mA
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.
10 more parts have no package on record
- PJQ2568Aprinted 568MOSFET, PanjitMOSFETNot recordedNot recordedPanjit
  Printed 568 on the part. Easy to misread as SCB. Check that character with a loupe before you order anything.
  What it is
  MOSFET
  Maker
  Panjit
  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 PJQ2568A, opens in a new tab
- PTZTF5.6Bprinted 5.6BZener diode, ROHMZener diodeNot recordedNot recordedROHM
  Printed 5.6B on the part. Easy to misread as SCB. Check that character with a loupe before you order anything.
  What it is
  Zener diode
  Maker
  ROHM
  Package
  Not recorded
  Pins
  Not recorded
  Details
  Zener Diode (AEC-Q101 qualified)
  Source
  Manufacturer datasheet
  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 PTZTF5.6B, opens in a new tab
- ECL112139BFRprinted S68LDO regulator, E-CMOSLDO regulatorNot recordedNot recordedE-CMOS
  Printed S68 on the part. Easy to misread as SCB. Check that character with a loupe before you order anything.
  What it is
  LDO regulator
  Maker
  E-CMOS
  Package
  Not recorded
  Pins
  Not recorded
  Details
  Linear voltage regulator IC: LDO, 3.9V±2%, 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.
- ECL112142BFRprinted S6BLDO regulator, E-CMOSLDO regulatorNot recordedNot recordedE-CMOS
  Printed S6B on the part. Easy to misread as SCB. Check that character with a loupe before you order anything.
  What it is
  LDO regulator
  Maker
  E-CMOS
  Package
  Not recorded
  Pins
  Not recorded
  Details
  Linear voltage regulator IC: LDO, 4.2V±2%, 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.
- HZF5.6BPprinted 5.6BZener diode, RenesasZener diodeNot recordedNot recordedRenesas
  Printed 5.6B on the part. Easy to misread as SCB. Check that character with a loupe before you order anything.
  What it is
  Zener diode
  Maker
  Renesas
  Package
  Not recorded
  Pins
  Not recorded
  Details
  Z-diode: 5,6V±5%, 900mW
  Source
  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.
- IXD3236A2BC0R-Gprinted 5CBDC-DC converter, IXYSDC-DC converterNot recordedNot recordedIXYS
  Printed 5CB on the part. Easy to misread as SCB. 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, 2.15V±2%, 600mA, 1.2MHz, 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.
- IXD3236A2BC4R-Gprinted 5CBDC-DC converter, IXYSDC-DC converterNot recordedNot recordedIXYS
  Printed 5CB on the part. Easy to misread as SCB. 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, 2.15V±2%, 600mA, 1.2MHz, 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.
- IXD3236A28C0R-Gprinted 5C8DC-DC converter, IXYSDC-DC converterNot recordedNot recordedIXYS
  Printed 5C8 on the part. Easy to misread as SCB. 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, 2.8V±2%, 600mA, 1.2MHz, 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.
- IXD3236A28C4R-Gprinted 5C8DC-DC converter, IXYSDC-DC converterNot recordedNot recordedIXYS
  Printed 5C8 on the part. Easy to misread as SCB. 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, 2.8V±2%, 600mA, 1.2MHz, 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.
- LN1130P392VRprinted S68LDO regulator, Shanghai Natlinear ElectronicsLDO regulatorNot recordedNot recordedShanghai Natlinear Electronics
  Printed S68 on the part. Easy to misread as SCB. Check that character with a loupe before you order anything.
  What it is
  LDO regulator
  Maker
  Shanghai Natlinear Electronics
  Package
  Not recorded
  Pins
  Not recorded
  Details
  Linear voltage regulator IC: LDO, 3.9V±2%, 300mA
  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.

54 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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