Let me start by saying that these are no ordinary computer power supplies. They are Delta 335 watt supplies that come from IBM PS/2 Servers. They are rather complicated inside. This is a long post, but please bear with me.
The mode of failure is that the supply just plain quits...mine have either died silently while running or have not come back on after power failures. There are no signs of distress in these supplies--they just quit running out of the blue.
As a PS/2 collector and hobbyist who keeps his PS/2s in regular use, I find this failure very troubling. These supplies are solidly built...it is hard to imagine them just silently dying, but that is what happens. Conversation with others who have these systems have revealed that this is not something happening only to me.
I am desperately seeking assistance in troubleshooting these supplies. I don't have the skills or comfort level to diagnose them. What I'm looking for is someone who would be willing to have a look at these supplies and at least provide a reason for their failure. If they can be fixed--that's great--but it is not the primary goal. I want to know *why* they died.
Sam Goldwasser (whom I sincerely hope does not mind my mentioning his name) looked at one of the supplies and was able to find out some information--if my understanding is correct, he found that the standby supply was working but the TL494 controller was being told to shut down with the "dead time control" pin 4.
I'd really appreciate any help with these supplies. I'm desperate for help and running out of places to look. I am more than willing to pay for your time and shipping of the supply both ways.
If you can help, please post back here to the group or send an e-mail to: wct walshcomptech com. Thank you.