SMD code U4B
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.
6 parts are printed U4B
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.
IXD5118N14BMR-GSOT-23-5Voltage supervisor, 5 pins, IXYSVoltage supervisorSOT-23-55 pinsIXYS
- What it is
- Voltage supervisor
- Maker
- IXYS
- Package
- SOT-23-5
- Pins
- 5
- Details
- Voltage detector IC: 1.4V±30mV, ±Reset ODO, Sense, Hst <1%, Cd
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
MURA110SMARectifier, 2 pins, onsemiRectifierSMA2 pinsonsemi
- What it is
- Rectifier
- Maker
- onsemi
- Package
- SMA
- Pins
- 2
- Details
- 1A, 100V, 35ns, Surface Mount Fast Recovery Rectifiers
- Source
- Published code list
Is it dead? The meter test is below: Silicon diode.
XC6118N14BMR-GSOT-23-5Voltage supervisor, 5 pins, TorexVoltage supervisorSOT-23-55 pinsTorex
- What it is
- Voltage supervisor
- Maker
- Torex
- Package
- SOT-23-5
- Pins
- 5
- Details
- Voltage detector IC: 1.4V±30mV, ±Reset ODO, Sense, Hst <1%, Cd
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
3 more parts have no package on record
IXD5118N14BGR-GVoltage supervisor, IXYSVoltage supervisorNot recordedNot recordedIXYS
- What it is
- Voltage supervisor
- Maker
- IXYS
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Voltage detector IC: 1.4V±30mV, ±Reset ODO, Sense, Hst. <1%, Cd
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
S-8333CCAB-I8T18 pins, ABLICNot recordedNot recorded8 pinsABLIC
- What it is
- Not recorded
- Maker
- ABLIC
- Package
- Not recorded
- Pins
- 8
- Source
- Published code list
Is it dead? The meter test is below: This part.
XC6118N14BGR-GVoltage supervisor, TorexVoltage supervisorNot recordedNot recordedTorex
- What it is
- Voltage supervisor
- Maker
- Torex
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Voltage detector IC: 1.4V±30mV, ±Reset ODO, Sense, Hst. <1%, Cd
- Source
- Published code list
Is it dead? The meter test is below: Integrated circuit.
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.
Integrated circuit
Voltage with the board powered; ohms from each pin to ground with it off.
Working, it reads
Supply pin at its voltage and the output doing what the datasheet says. Readings between pins depend on the part.
Dead, it reads
- A pin near 0 Ω to ground or to the supply pin where an identical part does not read that: failed short.
- Supply present, output stuck: failed, or its load has.
- On the board:
- A pin shorted to ground on the board can be anything on that net. Lift the pin to be sure.
- Compare:
- The surest reference is the same IC on a working board, measured pin by pin.
- Watch for:
- Its protection diodes can read like junctions between pins, even like a transistor. That proves nothing either way.
A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.
Silicon diode
Diode range, part lifted or one leg off the pad. Red probe on the anode.
Working, it reads
About 0.5 to 0.8 V anode to cathode, and open the other way. Small switching diodes read about 0.6 to 0.7 V; large rectifiers can read a little lower.
Dead, it reads
- The same reading both ways round, near 0 V with a continuous beep or the same middling value: shorted.
- Open both ways: failed open.
- A reading the wrong way round as well: leaky.
- On the board
- this is a first look only: the meter reads every path between those pins, and a short can be a neighbour. Lift one leg before you condemn it.
- Compare:
- If an identical part sits elsewhere on the board, measure it the same way: that is what this one should read.
- Watch for:
- A three-pin body can hold two diodes. With a common pin they read two junctions from that pin, just like a transistor; in series they read two drops end to end. Test each pair the datasheet names.
A dead part still carries its marking. A short or an open says it has failed, not that it is a different part.
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 U4B
One character differs, and it is one that is easy to confuse under a lamp. Each code has a page of its own.
Codes that begin with U4B
For a marking with its end worn or burnt off. Each code has a page of its own.
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