One day I got my hands on a Prosignia 200 with a broken power supply. The internal fuse was blowing as soon power was applied to it. I had three options what do do with it:
- Salvage some useful parts and throw the leftovers in the garbage.
- Buy a new (expensive) spare part PS from Compaq.
- Try to fit a cheap ATX PS that I had a laying around in a junk drawer.
Compaq, in its wisdom, is using a special power supply in Prosignia - why use an industry standard power supply when you can design your own and sell more spares?
The Prosignia PS uses two headers on the motherboard - J17 that looks just like a standard 12-pin AT PS header and J50 with 11 pins.
Since I haven't found any documentation on the net regarding the pinout of J17/J50 I had to try to figure it out myself. By dismantling the broken PS looking at the PCB for some clues and using my trusty old DVM to check for continuity between the PS-pins and points at the MB known to be fed by a certain voltage I've come up with a solution that works for me.
To actually connect the new PS to the MB I had to cut off and discard the ATX header from the new PS, and cut off the old PS itself from the two cables that connects to J17/J50. Then I connected the cables as shown below:
In a normal computer both the power switch and power led are connected to the MB, in the Prosignia they were connected inside the old PS. I cut off the cables from the PS and connected them as shown below. Note that the red wire is ground and the black is positive on the power led!
The physical dimensions of the new PS don’t match the old one, so it's impossible to use the old mounting holes and screws. Gluing the PS to the back inside of the cabinet solved that problem. I used melting glue, but I suppose that epoxy is even better.
I must admit that it doesn't look pretty at all, but it works. And that's the most important thing for me.
