I'm not aware of any extant schematics or service manuals for that particular machine, but I can perhaps offer some general guidance if it would be helpful to you. A lot of those PC power supplies are pretty similar in topology and I've fixed a whole crap ton of them. Question - does it try to start? As in, can you hear it go "tick" and see the fan twitch or things hooked up to it try to light up? A very common problem in this era of supply (and power supplies in general from 40yrs ago) is the output caps going bad, so the supply can't properly regulate and shuts itself down. Also, lot of them use a small value cap (maybe 47uF or so) on the primary to "kick start" the switching circuit; it commonly goes bad, and will cause a no start condition. This sometimes manifests in a situation where the supply only starts after being plugged in for a long time (leaky cap slowly charging up). The way you talk about output voltages makes me assume the fuse is probably OK and it's at least trying to do something, so hopefully no blown up switching transistors or anything that would be a bigger headache to diagnose. Let me know if this is helpful! Regards, CJ On Sun, Mar 10, 2024 at 1:30 PM Sentrytv via vcf-midatlantic < vcf-midatlantic@lists.vcfed.org> wrote:

Good afternoon

I believe I have posted before with a question about a keyboard for this computer (386-20), but now I have a question about a schematic diagram for the power supply. I am looking to repair the power supply which is currently dead, outputs about .5 V -.5 V and that’s it. Nothing obviously open or shorted. Somebody did have their hands in it prior to me, replacing or at least soldering various transistors.

My issue is: I would like to find a schematic diagram for this so that I can do repairs myself. Or at the very least, connect an AT power supply or hook up an ATX power supply to get the computer running.

I would need to know what voltages besides the obvious 12 V, 5 V , -12 V ,-5v needed to run this system.

If anyone has experience performing such a task, Please contact me directly if necessary.

I won’t bring it to the workshop unless I can find someone who knows, and I have a schematic diagram in hand.

Thank you Mike Rosen

Sent from: My extremely complicated, hand held electronic device.