SMD marking
18N
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.
18N on a chip capacitor
18 nF
18 nF capacitor
The n is both the decimal point and the unit: 18 nF.
Check it with a meter
Lift one end and measure it on a capacitance range. A good one reads close to 18 nF. In circuit the meter also sees everything connected across it, so the reading means little until it is out. A failed one usually reads near 0 Ω, or a steady low resistance, on the ohms range, often from a crack. On the board a shorted capacitor shorts its whole rail. A failed reading does not change what to fit: the marking still says 18 nF.
On a transistor or diode body (SOT-23), 18N is a part code instead. Those parts are listed below.
The only part printed 18N in our tables
TLV62568PDRL
- What it is
- DC-DC converter
- Maker
- Texas Instruments
- Package
- Not recorded
- Pins
- 6
- Details
- 1-A High Efficiency Synchronous Buck Converter in SOT Package
- Source
- From the manufacturer's datasheet
Is it dead?
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.
1 more part has a code that begins with 18N
Codes that begin with 18N
For a marking with its end worn or burnt off. Each one shows its full printed code.
TL432LIAQDBZprinted 1BNPSOT-23Voltage reference, 3 pins, Texas InstrumentsVoltage referenceSOT-233 pinsTexas Instruments
Printed 1BNP. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
- What it is
- Voltage reference
- Maker
- Texas Instruments
- Package
- SOT-23
- Pins
- 3
- Details
- Programmable Shunt Regulator with Optimized Reference Current
- Source
- From the manufacturer's datasheet
Is it dead?
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.
Open this in the search to correct a character or try another package.