Hello group,
I discovered I have a Dynacomp PSU thst will change the +5/-5 rails drastically after 15-20 minutes of being powered. They hold a good 5.03/-5.12 for 15-20 minutes then I see them (dropping on the +5 and increasing in the -5). Will change from 5.03/-5.12, minute later 5.02/-5.11, minute later 5.01/-5.10 it will keep going. I left the room for a few minutes and when I came back they were at 3.45/-3.75. I shut it down. After a full recap it did the same thing. After I shut it off for 5 seconds and power back up it holds fine for the same 15-20 minutes before changing again. I’ve read several posts here in PSU issues and I have a feeling this problem is deeper. First time I’ve seen this happen with a PSU.
Any input would be appreciated.
Thanks
It sounds like there's a problem in the feedback of the switcher. Without a schematic it's hard to say, but for example, if it uses a TL431 or optocoupler for the feedback, those may need replacement.
Thanks for the reply,
I couldn’t find a schematic for this Dynacomp. I remember looking months ago when I was recapping PSUs. Astec schematic yes Dynacomp no soap. I would like to repair it if possible before throwing in the towel.