Dell NPS-730AB A - Intermittent shut-down?

[Logistics]

Have this supply out of a Dell rack that will run for a while, maybe an hour, then fail. Techies at my company is a network guy and has no idea how to sling solder so I said I'd look at it for him. He already replaced the supply and the system is normal, again but he'd like to fix this psu.

I don't see any vented or bulging caps, but they are all crappy L-tec and Taicons save for the UCC mains. Any ideas?

[Phaihn]

Re: Dell NPS-730AB A - Intermittent shut-down?

the caps could be bad without looking bad.
also post pictures if you can.

[Pentium4]

Re: Dell NPS-730AB A - Intermittent shut-down?

the caps could be bad without looking bad.
also post pictures if you can.

Especially the Ltec. Taicon actually aren't as bad as they may seem, they can last quite a while and handle heat decently. Much better than Teapo can. I still replace them if I can though...You could recap it and see if that fixes it but my gut is telling me this isn't a cap issue

[Logistics]

Re: Dell NPS-730AB A - Intermittent shut-down?

My gut tells me you're likely correct. Though there are some missing and undersized caps, some right up next to regulators... tough to spend $10-$20 just to try.

[PeteS in CA]

Re: Dell NPS-730AB A - Intermittent shut-down?

An hour ... could a fan be not working and the thing heats up into thermal shutdown?

If it has either a UC384x PWM or one of those PFC-PWM combo custom ICs, check to see if it has a low value GP lytic cap for start-up. Those can go bad without venting.

Maybe a similar kind of thing with the O/P cap of the +5V Stby?

Delta's office is in Fremont, just off I-880 (Fremont Blvd exit, on Cushing Pkwy). They do have tech support people there, though not sure they could help.

[PeteS in CA]

Re: Dell NPS-730AB A - Intermittent shut-down?

... some missing and undersized caps ...

The PCB may be laid out and used for more than one model and those other models might use the "missing" or larger parts.