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ScutBoy
June 25th, 2017, 04:04 PM
I'm looking for a replacement power supply for an original Compaq Deskpro system.

Current supply seems completely dead - no activity at all when power is applied.

As you can see from the photos, there was likely moisture involved at some point, though the rest of the inside of the machine looks good.

There is a stamped number "101086 M-M" on the PS case, but no other part number indicated.

Or - you can see the pinout of the PS connections to the motherboard. I suppose one could make an adapter from a more modern supply to these voltages.

If anyone has the part, or words of wisdom on adapters or repair of the existing supply, I'd appreciate it! I haven't opened the PS case yet to see what might be going on inside...

Steve

https://flic.kr/s/aHsm3c1y7Q

zombienerd
June 25th, 2017, 04:42 PM
The voltages seem to be printed right on the board with nice divisors. I'd say any AT power supply would work if you removed that ribbon cable and soldered in the wires where necessary. Any ATX supply would work if you got a -5V DC/DC converter that are sold at a few places online.

Next is just making sure that the physical size and power cable location of the supply you choose matches, as you can always drill new mounting holes.

Or, keep your eyes on fleabay or post in the wanted section on the forum, maybe someone has an original.

There's also the option of repairing the PS you have. That would take some basic electronics knowledge, test equipment, and soldering skills if you plan to do it yourself. Start tracing where the power input hits the board, and look for fuses, blown components, etc. It could be as simple as a blown inline fuse somewhere.

zombienerd
June 25th, 2017, 04:43 PM
You should take the cover off the power supply and post a few high res pics of the board(s) inside. It would help a lot :)

bear
June 26th, 2017, 08:21 AM
I haven't been inside an original Deskpro, but if it resembles the original Portable at all, it's more likely one of the tantalum capacitors on the mainboard (or elsewhere in the system) is shorted, and putting the PSU into overcurrent protection. This would manifest as "no life at all".

Since the shorted tantalum hasn't exploded, the short is probably not on the 5V rail, which should significantly cut down on the number of capacitors to check. If you haven't started by removing all the expansion cards, start there.

Al Kossow
June 26th, 2017, 08:51 AM
The voltages seem to be printed right on the board with nice divisors. I'd say any AT power supply would work if you removed that ribbon cable and soldered in the wires where necessary. Any ATX supply would work if you got a -5V DC/DC converter that are sold at a few places online.

Next is just making sure that the physical size and power cable location of the supply you choose matches, as you can always drill new mounting holes.


Find an original supply, rather than butchering your machine.

Casey
July 3rd, 2017, 08:33 PM
I haven't been inside an original Deskpro, but if it resembles the original Portable at all, it's more likely one of the tantalum capacitors on the mainboard (or elsewhere in the system) is shorted, and putting the PSU into overcurrent protection. This would manifest as "no life at all".

The power supplys are very different between the Deskpro models and the Portables.

I have a spare Deskpro 286; well half of one. Some friends tossed the cover so what I have are the guts and the chassis. Was going to pick up a Deskpro386 motherboard to drop in but I waited too long, someone else snapped it up.

I might consider selling you this P/S. If memory serves the Deskpro and Deskpro286 had similar form factors. After that would consider selling the chassis & motherboard, or (as zombienerd suggested) I might adapt an ATX power supply. I've also considered using the chassis for a test rig, but I'd have to cut metal to get a standard AT motherboard to fit that sucker.

ScutBoy
July 4th, 2017, 06:45 AM
Casey,

From what I know I believe you are correct - I think the Deskpro and Deskpro 286 may have the same PS. If you would consider selling, a couple of pictures for comparisons sake would be great. I've not been able to find much info on these power supplies anywhere, though my google-fu may not be the greatest.

bear
July 4th, 2017, 01:06 PM
The power supplys are very different between the Deskpro models and the Portables.

Cripes, you don't think maybe I meant, in the full context of this thread, that the resemblance of interest might be in the use of tantalum capacitors on the motherboard?