SMD code search: identify a part by its marking
1 printed with a similar-looking code.
Nothing is printed exactly 510A
This part is printed with a character that is easy to misread as what you typed. The odd one out is marked on each.
LM2681M6printed S10ASOT-23-66 pins, National SemiconductorSOT-23-66 pinsNational Semiconductor
Printed S10A on the part. Easy to misread as 510A. Check that character with a loupe before you order anything.
- What it is
- Not recorded
- Maker
- National Semiconductor
- Package
- SOT-23-6
- Pins
- 6
- Details
- Linear IC: Switched Capacitor Voltage Converter 2.5..5.5V, 20mA
- Source
- Published code list
Is it dead?
Ohms range across it, and a capacitance range with it lifted.
Working, it reads
On the ohms range it reads open, or climbs to open as it charges. Lifted, a capacitance range reads close to its value.
Dead, it reads
- Near 0 Ω, or a few ohms: shorted. The usual failure, often from a crack caused by board flex or heat, and it can come and go.
- A steady resistance, kilohms rather than open: cracked and leaking.
- Lifted, far below its value on a capacitance range: cracked open or drifted. Less common than a short, but it happens.
- On the board
- a shorted capacitor shorts its whole rail, so every capacitor on that rail reads the same short. Lift one end, or feed the rail from a current-limited supply and feel which part warms up.
- Compare:
- Chip capacitors are mostly unmarked, so the value comes from the schematic or the same position on a working board.
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 510A: none in SOT-23-6, 1 with no package on record
Codes that begin with 510A
For a marking with its end worn or burnt off. Each one shows its full printed code.
1 part has no package on record. Nothing rules it out, so it stays.
SS510ALHprinted 510ALHSchottky diode, Taiwan SemiconductorSchottky diodeTaiwan Semiconductor
Printed 510ALH. Only the start matches what you typed, so this fits only if the rest of the marking is worn off.
- What it is
- Schottky diode
- Maker
- Taiwan Semiconductor
- Package
- Not recorded
- Pins
- Not recorded
- Details
- Rectifier schottky
- Source
- Manufacturer datasheet
Is it dead?
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.
Did you find your part?
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One code, several parts
Marking codes are not unique. In the standard code book, 6H on a SOT-23 is an NPN transistor, a varicap, an N-channel JFET, two digital transistors, a 3.6 V voltage detector: six parts from five makers. So a search on WhatSMD (What SMD) shows the parts we hold under that code and under codes easily misread as it, with only the columns that tell them apart.
- NPN transistor
- Varicap
- N-channel JFET
- Digital transistor ×2
- 3.6 V voltage detector
When more than one is left
Tap Help me choose. Up to 4 quick answers: whether the part has failed, then what separates the parts left. Those get ranked with the reasoning and a test that settles it. That uses one identification: 2 a month are free without an account, and 3 with a free account.
When you cannot read it
Tap the camera in the field. We read the characters, keep the ones we are unsure of, and search every reading. A photo too soft to read is turned back on your phone first; if it is the only one you can get, you can still send it.
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