My old Packard Bell PSU stopped working. Could I replace it with a PC AT power supply?

The montherboard layout doesn't look like a true AT, but it has a 12 pin connector that sure looks as if it would accept a PC AT PSU. I just don't want to fry anything.

Why do you think it's the PS that's the problem?
Check your PS.
See response 4 in this:
http://www.computing.net/hardware/w...

Some old mboards made after ATX PSs came out and before 2000 had both AT and ATX main power connectors on them.

You could try the AT main connectors to see whether they fit properly - the black wires go in the center. If they do, I know of no other connector they would fit on.

However, it's possible the mboard and the PS have proprietary wiring, and not standard ATX or AT wiring.

If you supply the PBell model number I might be able to confirm whether your mboard has that.

If it is a standard AT connector and wiring.......

The drawbacks are.....
- the AT PS must have enough capacity - probably at least 140 watts
- the two pins for the power switch on the mboard will no longer work with the case ATX (momentary contact) power switch.
- you will have to remove the ATX power switch from the case and install the AT one which is connected directly to the PS. They are different types of switches (the AT one is either on or off, the ATX one is momentary contact, on only when pressed).
- the mboard will no longer shut down all the way automatically when you shut down Windows - you will have to switch off the power switch.
- you may no longer be able to "wake up" the computer with the movement of a mouse, or by pressing a key, etc.

The wiring on Packard Bell is standard. The problem is the size of the power supply is much smaller in length and if you fit a standard power supply the CD rom drive won't fit all the way in.
One of the new drives may be short enough, as they are about an inch shorter than the old ones.

That's probably an LPX-based computer; Packard Bell produced a ton of them back then. All of the expansion slots are on a daughtercard, right?

Here's what Wikipedia says about powering LPX computers with AT supplies:

"The internal PSU connector was of the same type used in the AT form factor; most LPX cases were compatible with AT power supplies, though some used models that were smaller than standard, and usually manufacturer-specific."

So, if the case accommodates the AT PSU, you're good to go. If it doesn't, use the handyman's secret weapon: duct tape. :-)

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What anmor and jackbomb are saying is often but not always true.
Some PBells have standard sized power supplies, some don't; if it is a horizontal desktop or slim desktop model it's probably LPX; if it's a tower it probably has a regular mboard.
If you supply the PBell model I or they might be able to tell you more.

E.g. I have two old PBells, both horizontal slim desktops, both have LPX mboards, both use a standard sized PS.

If you're handy & aren't overally attached to the PC, you could always mod the case to make it accept a standard ATX PSU.

I was given an old P2 tower a while back that a bad PSU (mATX). I had several standard 250W ATX units kicking around so I just cut a rectangular hole in the back of the case, slid the PSU in from the outside leaving enough clearance between the PSU & CD-ROM drive, then secured it in place with a couple of sheetmetal screws. It's a bit odd looking with 2" of the PSU protruding outside of the case, but it works fine.

My nephew's retired PBell is a full sized tower (Milano case). Regular mboard (Intel AL440LX). The PS has a proprietary box, fan in a projecting smaller box on the bottom of it, no fan towards back just vent openings, standard ATX wiring. It appears a standard sized PS would fit fine, but might have to modify the openings on the back of the case.

If this mboard is old enough it has both AT and ATX power connectors on the mboard, I doubt it has a tiny mATX PS, but it might have a larger one that is not in a standard box.

I assume onion.ring already has an AT PS he is wondering if he can use.

Yeah, I think it is an LPX. It does have a riser card with expansion cards on it. But it's a tower, not a slimline. Its a very strange looking case.

I'm not home at the moment but the AT PSU looked as if it would mount properly in the tower.

So there shouldn't be a problem then?

Oh yeah, there's no ATX connector, just an AT one.

Some not slim horizontal desktops could be used as towers as well.

"So there shouldn't be a problem then?"

Probably not, as far as the wiring being compatible, but if you supply the PBell model number, I or we may be able to dig up info and tell you for sure.

Well, the AT PSU seems to work great! Thanks for the help, guys!