opto something Liteon 816A4

[jm1234]

Hi,
I'm troubleshooting a power supply board and one opto coupler seems shorted. It's a through-hole, marked with 3 lines:
1223
816A4
W
I'm not sure what replacement to buy for it. It resembles LTV-816 (https://www.tme.eu/sk/en/details/ltv...output/liteon/), but I'm not sure it's 100% that. The data sheet shows multiple sub-types like 816M, 816S, but 816A is not there.
I do have other functional pieces on the same board, so I could do some measurements on those, but I'm not sure what to check.
Any idea appreciated.

[harp]

When you desolder optocoupler from board, so it is off circuit, check in diode mode between leg#1 and 2, an later betveen leg#3 and 4 on optocoupler in both direction.
Whats is readings?

[jm1234]

0 resistance between 1 and 2, that's why I wrote it's shorted. My question was more to what could I replace it with.

[harp]

I dont know for sure. Some standards are 817, so may or may not be critical for choosing 816 instead by design.
Here is compare, a few point is different.
https://www.utmel.com/compare/HCPL-8...V-816--4824806

[truclacicr]

I think you are misinterpreting the datasheet.

LTV-816 comes in a DIP (page 2)
LTV-816M is a wide lead spacing package
LTV-816S is a surface mounting package

"A2" is the rank (page 3),

Rank mark "A" denotes a CTR (current transfer ratio) of 80 - 160. (page 10)

https://www.tme.eu/Document/5aee6f35...fd/LTV-816.pdf

[jm1234]

You're probably right in that, but there is no way to order specific rank as far as I can tell, so that seems puzzling. Anyhow, I ordered that LTV-816 from TME and what arrived is labeled 816B. I put it on the PCB and the issue is gone now. So I consider this a success, knowing well it's too soon to claim any victory here.

[truclacicr]

The ordering information is towards the end of the datasheet.