How about some pics of the PSUs in question?

SFX is a pretty new standard, I wouldn't reckon that old systems like this will have it.

"AOpen Custom PC" could be many things. A lot of AOpen uATX cases came with a long PSU, a tiny bit thinner than SFX but twice as long. But that's a full ATX motherboard, so without any further info I'd guess a normal ATX PSU, probably an AOpen-branded FSP model.
Compaq tended to use proprietary 24-pin PSUs or AT-like-but-different connectors around the P2 era.
Packard Bell "Multimedia" systems had totally different designs/models per market/country, so googling that "S610" gives me three different case types. However PB tended to be pretty standard when it came to PSUs and all the models are from the pre-ATX era, so I'd expect pretty generic AT PSUs in there.

The Compaq / Mitac PSU (P/N 319235-001) is proprietary dimension-wise rather than standard SFX. Also seen mention (against ATX PSU testers) that it may not use standard ATX wiring either.

https://www.ebay.co.uk/itm/Compaq-Presario-49 … 1-/381681798611

Packard Bell should be standard ATX PSU size, given that the ATX PSU size was derived from the "Baby AT/LPX" style Packard Bell's towers used.

AOpen isn't included in this list - see title. Let's start with the Packard Bell since it was the easiest for me to get to 😜 Certainly looks standard to me, but does anyone know if it will use standard wiring? Doesn't seem like a special proprietary PSU

Astec is good power supply. Do not worry about it, and standard format for baby AT type.

What's your the model of Compaq? Examples: Deskpro 4/33i, etc?

Cheers,

pentiumspeed wrote on 2020-07-24, 21:44:

Astec is good power supply. Do not worry about it, and standard format for baby AT type.

What's your the model of Compaq? Examples: Deskpro 4/33i, etc?

Cheers,

Company Presario 5170. See original specs here. I’ll try to get photos if needed this weekend!

Alrighty, here's the Compaq

Mitac is big company and still exist, also notebooks and some boards as well.

Looks good quality too, open the Mitac up and inspect capacitors brands.

Found some Mitac PSUs with -5V yay!

Cheers,

Resurrecting this thread instead of making a new one, got a few questions.

I inspected the PSUs at the time of the last post and didn't see any visible issues with the caps. Since then, the Compaq has begun to develop a dull but very high pitch whine that I haven't yet pinpointed from where it's coming. Decided to do another inspection of both systems and get some photos / videos this time. Would anyone be so kind as to glance over what I took? To me, everything still looks good, but I understand looks can be deceiving. Photos and videos can be found at this Dropbox link here.

Also, I've got a new EVGA 650 B5 that has good amperage on all rails for my ATX builds, but no -5V rail. I was considering using an ATX-to-AT adapter and transplanting it into the Packard Bell just to play it safe, but since that PSU has a -5V rail, I'm concerned about doing damage. I'm not familiar with what all utilizes -5V rails or even what happens if there's a lack of voltage on said rail in the presence of such devices. Would there be a risk / would there even be any such devices in that rig? See sig for details - it's the PB M.

Lastly, I've been slowly practicing basic soldering over the past five years (recapping an LCD mainboard, etc. - nothing to do with a PSU) and am planning to invest in a proper solder station, hot air station, preheater, etc. so that I can maintain my stuff over the coming years. In cases like my Packard Bell and Compaq, where the former has that -5V rail and the latter has a proprietary form-factor, would it make more sense to recap the OEM PSUs than to try installing new ones?

-5V is used on the ISA bus, mainly to power some sound cards. I'd expect that PB to have a 3rd gen Azetch card. I'm not sure whether it needs -5V, I know some older Aztechs do and some newer ones don't. Worst case that card doens't work. You can get AT-ATX converters that also do -5V to be sure. I'd recommend them if you go down this path.

My engineer's heart almost breaks at the thought of shoehorning an obscenely overpowered 650W PSU into there with an ATX-AT converter despite it working fine at the moment with a matching PSU. If you're worried about the state of the regular AT power supply, address that. Open it up, check the caps - visually at least - and in case of doubt replace them.

As for the noisy Compaq system: that's coil whine. You just need to find which coil it is and immobilize it with a blob of (hot) glue. If finding it is tricky, try to get a directional microphone and hook that up to a spectrum analyzer (spectrum analyzers for sound are available as Android app, no need for expensive kit here). Point it around until you see the big peak at high frequencies.

I don't know what screen you are using, but TFT monitors are notorious for starting to whine over time. It might not be the old desktop case after all...