twolazy
Veteran Member
I can relate, still have a few boards that are clean as new, and just refuse to show life... Do you have an eprom burner? Just to rule out bios corruption...
From what I see, the 8086 version of the Model 25 is XT class; suitability in that regard. The CGA card would need to be used.Anyone know if RUUDS diagnostic works on that machine? It should in theory ...
Yes, it would be good for someone who has one of these machines to verify. Ruud's diagnostic could display something, but one of more tests may fail due to the machine not being "100% compatible".... need someone with more knowledge of these machines to verify.
If you did want to do that (for peace of mind) they should be measured out-of-circuit. Not necessarily "easy", but just cutting one leg is enough, say, half way up the exposed part of the leg. Do the measurement, then 'blob' solder the two cut leg ends back together. Measure via the capacitance setting on your multimeter, or some other device that measures capacitance.I wish there was an easy way to test the tants.
Have you seen something that indicates that the Model 25's IBM BIOS ROM outputs codes to a parallel/LPT port ?I need to get one of those parallel port readers off eBay, just wish they didn’t take so long to get here lol
For a 1987 dated IBM BIOS ROM, one would hope so. Per [here], even on an IBM 5170 (IBM AT), a failure in the first 64 KB of RAM results in a 201 error being displayed, although a requirement for the 5170 is an MDA or CGA screen.I assume if it was a ram issue I would at least get some kind of a display or at least a beep.
Have you seen something that indicates that the Model 25's IBM BIOS ROM outputs codes to a parallel/LPT port ?
I dont think they are exactly the same, but my admittedly rudimentary understanding of the PS/2 series seems to point that from a diagnostic perspective at least they are similar enough that I should be abel to get some idea where its failing in the boot process with the codes. It's only $10 for a reader so I ordered one, figured cant hurt to try since im not making much headway from other angles.Is motherboard in model 30-8086 and 25-8086 the same?
I have retried reseating it a few times to no avail. Well, 8086's are cheap, I guess ill give a replacement a shot. If that doesn't work ill probably just move on from it at that point lol. Appreciate all the help so far guysCan you pull the cpu and reset it a couple of times? Spay the empty socket and cpu pins with Deoxit or IPA between pulls/inserts.
Do you have another machine to try the post code card in to make sure it works?
Yes, but so would quit a few other chips.Update, finally got the post code reader in. Its not posting any codes whatsoever unfortunately. Idk the board just seems dead its really strange. I can't figure out why it would be completely dead and not even attempting to post if the board and everything is getting power. I know a dead cpu is pretty rare but would a dead cpu cause it to not post any codes?
I think that a set of replacement ROM's are worth a shot.I have retried reseating it a few times to no avail. Well, 8086's are cheap, I guess ill give a replacement a shot. If that doesn't work ill probably just move on from it at that point lol.
I think that a set of replacement ROM's are worth a shot.
Do you guys know where I would go about getting a set of replacement roms for it? I dont own any flashing equipment, I know that might not be a bad investment at some point but can't really justify it right now. It's certainly something I would try if I knew where to get them.I really doubt the CPU has gone bad. I'd 2nd the suggestion to replace the ROMs.
See the list at [here].Do you guys know where I would go about getting a set of replacement roms for it? I dont own any flashing equipment, I know that might not be a bad investment at some point but can't really justify it right now. It's certainly something I would try if I knew where to get them.