SMD code 504
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.
5 parts are printed 504
Not sure which one you have?
Answer up to 4 quick questions and these 5 parts are ranked, with a meter test that settles it. It works on a dead part too.
ACGRC504-HFSMCRectifier, 2 pins, ComchipRectifierSMC2 pinsComchip
- What it is
- Rectifier
- Maker
- Comchip
- Package
- SMC
- Pins
- 2
- Details
- 400 V, 5 A rectifier
- Source
- Manufacturer datasheet
Is it dead? The meter test is below: Silicon diode.
R1191N104BSOT-23-5LDO regulator, 5 pins, RicohLDO regulatorSOT-23-55 pinsRicoh
- What it is
- LDO regulator
- Maker
- Ricoh
- Package
- SOT-23-5
- Pins
- 5
- Details
- Linear voltage regulator IC: LDO, 10.4V±1.5%, 300mA, +CE, ECO
- Source
- Published code list
Is it dead? The meter test is below: Voltage regulator.
S504TSOT-143RF amplifier (MMIC), 4 pins, VishayRF amplifier (MMIC)SOT-1434 pinsVishay
- What it is
- RF amplifier (MMIC)
- Maker
- Vishay
- Package
- SOT-143
- Pins
- 4
- Details
- biased dg mosfet MOSIC 5V uhf tv tuners
- Source
- Published code list
Is it dead? The meter test is below: RF amplifier.
SP0504SOT-23-55 pins, LittleFues Inc.Not recordedSOT-23-55 pinsLittleFues Inc.
- What it is
- Not recorded
- Maker
- LittleFues Inc.
- Package
- SOT-23-5
- Pins
- 5
- Details
- TVS AVAL DIODE ARRAY 4CH SOT23-5
- Source
- Published code list
Is it dead? The meter test is below: TVS or ESD protection diode.
SST504SOT-233 pins, CalogicNot recordedSOT-233 pinsCalogic
- What it is
- Not recorded
- Maker
- Calogic
- Package
- SOT-23
- Pins
- 3
- Details
- Current regulator diode
- Source
- Published code list
Is it dead? The meter test is below: Voltage regulator.
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.
Voltage regulator
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.
RF amplifier
Voltage, board powered, on the output pin that the bias resistor or choke feeds.
Working, it reads
The output pin sits at the device voltage the datasheet gives, a few volts, below the supply.
Dead, it reads
- Output pin at 0 V, or near 0 Ω to ground with the power off: shorted inside.
- Output pin at the full supply voltage: open inside, no current flowing.
- On the board:
- Measured on the board with power on; the bias network is part of the reading.
- 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 figures depend on the part and its bias resistor. 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.
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.
Printed with a code easy to misread as 504
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 504
For a marking with its end worn or burnt off. Each code has a page of its own.
Codes not listed here are printed on 77 more parts.
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