SMD code 74
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.
7 parts are printed 74
Not sure which one you have?
Answer up to 4 quick questions and these 7 parts are ranked, with a meter test that settles it. It works on a dead part too.
BAS70-04SOT-23Schottky diode, 3 pins, Taiwan SemiconductorSchottky diodeSOT-233 pinsTaiwan Semiconductor
- What it is
- Schottky diode
- Maker
- Taiwan Semiconductor
- Package
- SOT-23
- Pins
- 3
- Details
- SMD Small Signal Schottky Diodes
- Source
- From the manufacturer's datasheet
Is it dead? The meter test is below: Schottky diode.
BAS70-04WSOT-323Schottky diode, 3 pins, NexperiaSchottky diodeSOT-3233 pinsNexperia
- What it is
- Schottky diode
- Maker
- Nexperia
- Package
- SOT-323
- Pins
- 3
- Details
- SMD Small Signal Schottky Diodes
- Source
- From the manufacturer's datasheet
Is it dead? The meter test is below: Schottky diode.
BZX84-B24SOT-23Zener diode, 3 pins, NexperiaZener diodeSOT-233 pinsNexperia
- What it is
- Zener diode
- Maker
- Nexperia
- Package
- SOT-23
- Pins
- 3
- Pinout
- 1 anode
- 2 not connected
- 3 cathode
- Details
- 24 V ±2% voltage regulator (Zener) diode
- Source
- From the manufacturer's datasheet
Is it dead? The meter test is below: Zener diode.
RB160M-40SOD-123Schottky diode, 2 pins, JSCJSchottky diodeSOD-1232 pinsJSCJ
- What it is
- Schottky diode
- Maker
- JSCJ
- Package
- SOD-123
- Pins
- 2
- Details
- Schottky diode, 40 V, 1 A
- Source
- From the manufacturer's datasheet
Is it dead? The meter test is below: Schottky diode.
EIA-96:740603Precision resistor (EIA-96 code), 2 pinsPrecision resistor (EIA-96 code)06032 pinsNot recorded
- What it is
- Precision resistor (EIA-96 code)
- Maker
- Not recorded
- Package
- 0603
- Pins
- 2
- Details
- EIA-96 precision chip resistor, significand 57.6; the printed mark adds a multiplier letter (74A = 576 Ohm, 74B = 5.76 kOhm)
- Source
- Added by hand from a published table
Is it dead? The meter test is below: Resistor.
2 more parts have no package on record
SN74LVC2G74DCUFlip-flop, 8 pins, Texas InstrumentsFlip-flopNot recorded8 pinsTexas Instruments
- What it is
- Flip-flop
- Maker
- Texas Instruments
- Package
- Not recorded
- Pins
- 8
- Details
- Single Positive-Edge-Triggered D-Type Flip-Flop With Clear and Preset
- Source
- From the manufacturer's datasheet
Is it dead? The meter test is below: Integrated circuit.
VSKY1540C9Schottky diode, VishaySchottky diodeNot recordedNot recordedVishay
- What it is
- Schottky diode
- Maker
- Vishay
- Package
- Not recorded
- Pins
- Not recorded
- Details
- 74
- Source
- From the manufacturer's 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.
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.
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.
Resistor
Ohms range, across it, power off.
Working, it reads
Its marked value, within tolerance. On the board it reads the same or lower, because everything around it sits in parallel.
Dead, it reads
- Open: burnt, cracked, or eaten through by sulphur. The commonest failure.
- Well above its marked value: drifted high.
- On the board, clearly higher than its marked value: it has failed, since the board can only pull a reading down.
- On the board:
- A reading lower than marked on the board proves nothing; lift one end. A reading higher than marked is a fault even on the board.
- Compare:
- The same position on another channel usually carries the same value, and so does the matching part on another board.
- Watch for:
- A burnt resistor usually means the part it feeds pulled too much. Find that before fitting a new one, or it burns too. The marking, not the reading, says what to fit.
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 74
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 74
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 30 more parts.
Open this in the search to correct a character or try another package.