99 percent of the time it's the caps that go bad.

I ordered a new Startech AT PSU last year when I got a free 486 system and it's worked flawlessly so far.

anachronism1887 wrote:

I ordered a new Startech AT PSU last year when I got a free 486 system and it's worked flawlessly so far.

Second the Startech AT PSU. I put one in my AMD x5 a couple years ago and it has been fine so far.

I generally use AT power supplies with my AT motherboards, if it's an old one you can breathe some new life into it with a fresh set of caps, and there are also new units being sold (Startech are the most common, but not long ago I got a brand new FSP).

Assuming the capacitors are OK, one important thing to consider is that Pentium and earlier systems use very little power, so you generally won't be bringing an AT PSU to its knees in most cases, and not being stressed is good for the life expectancy of the unit (in fact, all the cheap AT power supplies I've ever owned since the early-mid 90's are still alive and they never killed a motherboard or other component).

The opposite scenario is the cheap ATX PSUs from the early 00's which had to deal with hungry Athlon XPs and video cards that were starting to ramp up power consumption. I lost quite a few of those until I realized I needed to buy better quality units.

In short, I would definitely use AT PSUs for older systems (with a recap if it's an older unit). For motherboards that have both AT and ATX power connectors I would use ATX though, no need to have the motherboard deal with the voltage conversion there.

.legaCy wrote:

AT PSU, but as PhilsComputerLab mentioned they are old and mostly unreliable and are known to die and kill other hardware parts when it happens.

That's a rather broad generalization. Is there evidence for this somewhere?

Although I have a rather small sample size when it comes to personal experience working inside AT PSUs, the ones I've seen came from a more industrial era of computing and had good circuit protection - X and Y caps, etc. If I had to decide to do a blind smoke test on a PC with an AT power supply from 1993 vs a PC with an ATX power supply from 2001, I would flip the switch on the AT. (Although in reality, I would use a spare PSU to fire up the system and open up both the old ones).

Has anyone opened these Startech PSUs to look inside? The assumption "newer is better" that I often see in the retro community when it comes to PSU usage is quite alarming.

CkRtech wrote:

That's a rather broad generalization. Is there evidence for this somewhere? […]
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.legaCy wrote:

AT PSU, but as PhilsComputerLab mentioned they are old and mostly unreliable and are known to die and kill other hardware parts when it happens.

That's a rather broad generalization. Is there evidence for this somewhere?

Although I have a rather small sample size when it comes to personal experience working inside AT PSUs, the ones I've seen came from a more industrial era of computing and had good circuit protection - X and Y caps, etc. If I had to decide to do a blind smoke test on a PC with an AT power supply from 1993 vs a PC with an ATX power supply from 2001, I would flip the switch on the AT. (Although in reality, I would use a spare PSU to fire up the system and open up both the old ones).

Has anyone opened these Startech PSUs to look inside? The assumption "newer is better" that I often see in the retro community when it comes to PSU usage is quite alarming.

Well ask him, the last time i used one at psu was 12 years ago.

cj_reha wrote:

99 percent of the time it's the caps that go bad.

Just the electrolytic ones or i should replace them all?

.legaCy wrote:

Just the electrolytic ones or i should replace them all?

It might be obvious when you open up the PSU!

In any case, I would replace them all... it'll be cheap enough, cheaper than a new PSU, and prob more reliable!