First post, by Whoo71
Hi All,
I picked up an old 286 last summer and have recently found some time to debug it to try and get it running (as it will not turn on). After finding nothing on Google or archive.org aside from this thread covering the same issue on a similar machine, I can conclude that there seems to be very little information on these machines.
I have yet to do any testing with a spare AT Power Supply to test the mainboard, but judging from the state of the power supply in it I'd say that it's a likely the culprit:
I've done some preliminary testing of components, during which I found:
- All resistors appear to be faulty, reading ohms well below what they're rated for
- Both diodes on the board appear to be shorted (~.6V in one direction, >2V in the other)
- The fuse isn't broken
So at this point I'm thinking my only option would be to replace every component in it, as it seems like there's a lot of stuff that's gone bad. However, I'm not sure how I would source certain components in it, like the transformers (which look like they may be the source of that residue all over the board?). Does anyone have any thoughts on going that route? Or would it be better to cut my losses and see if I can find a similarly sized AT power supply and stuff it in the enclosure here?
And for those interested in the system itself (as it sounds rare judging from the thread I linked), here are some pictures of the mainboard and the case:
