Please help with an equivalent IC for this burnt model in a PSU - Page 1
Forum section: electronics / repair

author: highcap
author_rank: Contributor
timestamp: February 28, 2024, 12:45:20 am
content: The machine I'm trying to restore is quite unique, and after cleaning this PSU I noticed that failed IC.As I can't find that exact model on sale, can someone help with getting an available equivalent?Thank you!H11A V2A 9434

author: wraper
author_rank: Unknown
timestamp: February 28, 2024, 12:53:18 am
content: It's a H11AV2A optocoupler. I have a big doubt that smoke came out of this part rather than something else. And if it's really failed explosively like this, it did not happen by itself and something else caused it instead.

author: fzabkar
author_rank: Super Contributor
timestamp: February 28, 2024, 01:04:56 am
content: Pin #3 is not connected.https://www.farnell.com/datasheets/172176.pdf

author: highcap
author_rank: Contributor
timestamp: February 28, 2024, 01:16:25 am
content: That's some bad news then... This means this optocoupler can never fail by itself?

author: fzabkar
author_rank: Super Contributor
timestamp: February 28, 2024, 01:18:59 am
content: Quote from: highcap on February 28, 2024, 01:16:25 amICBW, but I think that the failure mode of optocouplers is that they become "weak" over time.

author: minsik
author_rank: Contributor
timestamp: February 28, 2024, 01:31:19 am
content: Very nice clean power supply. Re the optocoupler you can remove it and test externally. Breadboard it and a small power supply, 1-15V maybe, add a load resistor to the output collector from the dc supply, emitter to ground, apply some limited mA to the input diode and does the output switch to ground? no its dead and likely o/c, yes its working. Normally optos are on or off and thus disapate only small amounts of power= no heat. Maybe look anything under the pcb that could get that hot to discolour the pcb? does the output go through those tracks that might explain the pcb heating, or was it something else nearby?Minsik.

author: coromonadalix
author_rank: Super Contributor
timestamp: February 28, 2024, 01:32:46 am
content: they become weak but not to explode like this or spit like this, something very strong pass thru it ??and may be an indicator of a major failure, no schematics = no good chances of repairing it ?

author: Muxr
author_rank: Super Contributor
timestamp: February 28, 2024, 02:24:44 am
content: Yeah, quite odd for an octo to be charred. Maybe a lightning strike?

author: highcap
author_rank: Contributor
timestamp: February 28, 2024, 11:45:01 am
content: You will be surprised about its shape from before I cleaned it, will add picsAlso the exploding trace can be observed on the dust near the octocoupler.I will probably need to investigate other bits of the PSU, but I really don't know where to start. I only know basic electronics.

author: inse
author_rank: Super Contributor
timestamp: February 28, 2024, 02:34:47 pm
content: That's 🤢 !In which environment did the device reside?Probably there was a flashover due to the dust layer, but then I would be looking for damage on the downstream circuit…

author: highcap
author_rank: Contributor
timestamp: February 28, 2024, 05:18:51 pm
content: That is powering up hard drives module of an industrial computer.It probably ran 24/7 for many years.Other modules/components does not look bad so I will probably have a hard time figuring out the culprit...

author: highcap
author_rank: Contributor
timestamp: June 06, 2024, 07:44:13 pm
content: Update: I have swapped out with a close equivalent (if not the same specs) and the PSU is powering up and running fine.Thank you all for your inputs.

author: highcap
author_rank: Contributor
timestamp: June 13, 2024, 11:35:28 am
content: UPDATE2 : For whoever might be interested about the underlying issue:Based on other findings about this hardware, the unit was affected by a struck caused by a thunderstorm. Something that some users suggested.There were a few things that indicate toward it, including a dead disk drive coupled inside the unit of this PSU, a dead PDU and even the blown power plug.Thank you all again.