SMD code 56s
Marking codes are not standardised, and the same code is reused by unrelated makers for unrelated parts. Below is every part in our tables printed with it, and any printed with a code that is easy to misread as it, from the manufacturers' own marking tables and published code lists.
56s on a chip resistor
37.4 Ω
37.4 Ω resistor, 1%
EIA-96 precision code: 56 selects 3.74 from the E96 series and S multiplies by 10. These are 1% parts. The trailing S is also used as a decimal point, so this could instead be 56 Ω. Measure it before fitting a replacement. If it has failed and reads open or high, that settles nothing: measure the same position on a working board.
Check it with a meter
Lift one end and measure across it. A good one reads 37.4 Ω within 1%. Measuring it in circuit reads the parallel combination of everything around it, which is almost always lower, never higher: well above 37.4 Ω on the board is a fault. Open, or well above 37.4 Ω, means it has failed: burnt, cracked or corroded. That does not change what to fit: the marking still says 37.4 Ω. A burnt resistor usually means the part it feeds drew too much, so find that before fitting a new one.
On a transistor or diode body (USP-6C, USP-6B, SOT-23), 56s is a part code instead. Those parts are listed below.
10 parts are printed 56s
Not sure which one you have?
Answer up to 4 quick questions and these 10 parts are ranked, with a meter test that settles it. It works on a dead part too.
BC856BSSOT-363Dual PNP transistor, 6 pins, PanjitDual PNP transistorSOT-3636 pinsPanjit
- What it is
- Dual PNP transistor
- Maker
- Panjit
- Package
- SOT-363
- Pins
- 6
- Details
- 65V, 0.1A, General Purpose Dual PNP Bipolar Transistor
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: PNP transistor pair.
BC856BS-AUSOT-363Transistor, 6 pins, PanjitTransistorSOT-3636 pinsPanjit
- What it is
- Transistor
- Maker
- Panjit
- Package
- SOT-363
- Pins
- 6
- Details
- Bipolar transistor
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Bipolar transistor.
MM3Z56SSOD-323Zener diode, 2 pins, Galaxy MicroelectronicsZener diodeSOD-3232 pinsGalaxy Microelectronics
- What it is
- Zener diode
- Maker
- Galaxy Microelectronics
- Package
- SOD-323
- Pins
- 2
- Details
- 56V, 400mW, Surface Mount Zener Diodes
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Zener diode.
TMM3Z56SSOD-323Zener diode, 2 pins, Galaxy MicroelectronicsZener diodeSOD-3232 pinsGalaxy Microelectronics
- What it is
- Zener diode
- Maker
- Galaxy Microelectronics
- Package
- SOD-323
- Pins
- 2
- Details
- 56V, 400mW, Surface Mount Zener Diodes
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Zener diode.
BAT17-06SOT-23Schottky diode, 3 pins, InfineonSchottky diodeSOT-233 pinsInfineon
- What it is
- Schottky diode
- Maker
- Infineon
- Package
- SOT-23
- Pins
- 3
- Source
- Published code list
Is it dead? The meter test is below: Schottky diode.
BAT17-06WSOT-3233 pins, InfineonNot recordedSOT-3233 pinsInfineon
- What it is
- Not recorded
- Maker
- Infineon
- Package
- SOT-323
- Pins
- 3
- Details
- dual cc BAT17
- Source
- Published code list
Is it dead? The meter test is below: This part.
MMBZ5256SPTSOT-23Zener diode, 3 pins, Chenmko EnterpriseZener diodeSOT-233 pinsChenmko Enterprise
- What it is
- Zener diode
- Maker
- Chenmko Enterprise
- Package
- SOT-23
- Pins
- 3
- Details
- Zener diode: 29.40..30.60V, Izt=5mA, Zzt=78, 225mW
- Source
- Published code list
Is it dead? The meter test is below: Zener diode.
MMCZ5256SPTSOT-23Zener diode, 3 pins, Chenmko EnterpriseZener diodeSOT-233 pinsChenmko Enterprise
- What it is
- Zener diode
- Maker
- Chenmko Enterprise
- Package
- SOT-23
- Pins
- 3
- Details
- Zener diode: 29.40..30.60V, Izt=5mA, Zzt=78, 225mW
- Source
- Published code list
Is it dead? The meter test is below: Zener diode.
MMHZ5256SPTSOD-123Zener diode, 2 pins, Chenmko EnterpriseZener diodeSOD-1232 pinsChenmko Enterprise
- What it is
- Zener diode
- Maker
- Chenmko Enterprise
- Package
- SOD-123
- Pins
- 2
- Details
- Zener diode: 29.40..30.60V, Izt=5mA, Zzt=78, 225mW
- Source
- Published code list
Is it dead? The meter test is below: Zener diode.
1 more part has no package on record
CDBAS560-HFSchottky diode, ComchipSchottky diodeNot recordedNot recordedComchip
- What it is
- Schottky diode
- Maker
- Comchip
- Package
- Not recorded
- Pins
- Not recorded
- Details
- 60 V, 5 A Schottky barrier diode
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Schottky diode.
Is it dead? One meter test per kind
Parts of the same kind are tested the same way, so each test is here once. Each part above points to its own.
PNP transistor pair
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.
Bipolar transistor
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.
Schottky diode
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.
Zener diode
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.
This part
Diode range and ohms range, part lifted.
Working, it reads
Depends on what it is. The datasheet, or an identical part, says.
Dead, it reads
- Between two pins, the same reading both ways, near 0 V with a continuous beep: shorted.
- Open between every pair of pins: failed open, or a part that reads open when working.
- On the board
- this is a first look only: the meter reads every path between those pins, and a short can be a neighbour. Lift one leg before you condemn it.
- Compare:
- If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.
Printed with a code easy to misread as 56s
One character differs, and it is one that is easy to confuse under a lamp. Each code has a page of its own.
Codes not listed here are printed on 6 more parts.
Did you find your part?
Open this in the search to correct a character or try another package.