SMD code 4Px
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.
The last letter, x, is lower case, which on NXP and Philips parts is a date or factory code, so it was set aside and 4P was searched.
77 parts are printed 4Px
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.
GSBAV3004WSOD-123Switching diode, 2 pins, Good-ArkSwitching diodeSOD-1232 pinsGood-Ark
- What it is
- Switching diode
- Maker
- Good-Ark
- Package
- SOD-123
- Pins
- 2
- Details
- Switching diode, 300 V, 225 mA
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Silicon diode.
L034AT25SOT-23-5ESD protection diode, 5 pins, Formosa MicrosemiESD protection diodeSOT-23-55 pinsFormosa Microsemi
- What it is
- ESD protection diode
- Maker
- Formosa Microsemi
- Package
- SOT-23-5
- Pins
- 5
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: TVS or ESD protection diode.
L034BT26L3SOT-23-6ESD protection diode, 6 pins, Formosa MicrosemiESD protection diodeSOT-23-66 pinsFormosa Microsemi
- What it is
- ESD protection diode
- Maker
- Formosa Microsemi
- Package
- SOT-23-6
- Pins
- 6
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: TVS or ESD protection diode.
MM1Z 5V6SOD-123Zener diode, 2 pins, HottechZener diodeSOD-1232 pinsHottech
- What it is
- Zener diode
- Maker
- Hottech
- Package
- SOD-123
- Pins
- 2
- Details
- Zener diode, VZ 5.6 V
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Zener diode.
MM1Z 5V6LSOD-123FZener diode, 2 pins, HottechZener diodeSOD-123F2 pinsHottech
- What it is
- Zener diode
- Maker
- Hottech
- Package
- SOD-123F
- Pins
- 2
- Details
- Zener diode, VZ 5.6 V
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Zener diode.
MM1Z5V6SOD-123Zener diode, 2 pins, HXYZener diodeSOD-1232 pinsHXY
- What it is
- Zener diode
- Maker
- HXY
- Package
- SOD-123
- Pins
- 2
- Details
- Zener diode, 27 V, 0.005 A
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Zener diode.
MM1Z5V6BWSOD-123Zener diode, 2 pins, JSMSEMIZener diodeSOD-1232 pinsJSMSEMI
- What it is
- Zener diode
- Maker
- JSMSEMI
- Package
- SOD-123
- Pins
- 2
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Zener diode.
MM1Z5V6WSOD-123Zener diode, 2 pins, HXYZener diodeSOD-1232 pinsHXY
- What it is
- Zener diode
- Maker
- HXY
- Package
- SOD-123
- Pins
- 2
- Details
- Zener diode, 22 V, 0.005 A
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Zener diode.
MM5Z4693SOD-523Zener diode, 2 pins, onsemiZener diodeSOD-5232 pinsonsemi
- What it is
- Zener diode
- Maker
- onsemi
- Package
- SOD-523
- Pins
- 2
- Details
- Zener Voltage Regulators MM5Z4xxxTxG Series, SZMM5Z4xxxTxG Series
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Zener diode.
TBAV3004WSOD-123Switching diode, 2 pins, Galaxy MicroelectronicsSwitching diodeSOD-1232 pinsGalaxy Microelectronics
- What it is
- Switching diode
- Maker
- Galaxy Microelectronics
- Package
- SOD-123
- Pins
- 2
- Details
- 0.225A, 300V, Surface Mount Small Signal Switching Diodes
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Silicon diode.
TBAV3004WSSOD-323Switching diode, 2 pins, Galaxy MicroelectronicsSwitching diodeSOD-3232 pinsGalaxy Microelectronics
- What it is
- Switching diode
- Maker
- Galaxy Microelectronics
- Package
- SOD-323
- Pins
- 2
- Details
- 0.225A, 350V, Surface Mount Small Signal Switching Diodes
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Silicon diode.
4 more parts have no package on record
GSEZ24U400ESD protection diode, Good-ArkESD protection diodeNot recordedNot recordedGood-Ark
- What it is
- ESD protection diode
- Maker
- Good-Ark
- Package
- Not recorded
- Pins
- Not recorded
- Details
- ESD protection diode, VRWM 24 V
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: TVS or ESD protection diode.
SBESD24-CESD protection diode, SeCoSESD protection diodeNot recordedNot recordedSeCoS
- What it is
- ESD protection diode
- Maker
- SeCoS
- Package
- Not recorded
- Pins
- Not recorded
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: TVS or ESD protection diode.
SM4NT220ATVS diode, Formosa MicrosemiTVS diodeNot recordedNot recordedFormosa Microsemi
- What it is
- TVS diode
- Maker
- Formosa Microsemi
- Package
- Not recorded
- Pins
- Not recorded
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: TVS or ESD protection diode.
TBAV3004HESwitching diode, Galaxy MicroelectronicsSwitching diodeNot recordedNot recordedGalaxy Microelectronics
- What it is
- Switching diode
- Maker
- Galaxy Microelectronics
- Package
- Not recorded
- Pins
- Not recorded
- Details
- 0.225A, 350V, Surface Mount Small Signal Switching Diodes
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Silicon 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.
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.
TVS or ESD protection diode
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.
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.
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