by Y-my-R » Tue Jan 15, 2019 8:15 pm
Most of the time, removing the battery for a few hours has the same effect as clearing the CMOS via a jumper, so you can just try that first. I don't remember where the jumper to clear the CMOS is, but the mainboard manual says it. Just search for "Amptron PM-9800". I think that's the "old board"... and if so, it's Jumper 1 (SP1... looks like it's next to the ISA slots, on the side towards the processor.
Other than that, and after you tried removing the battery, a standard troubleshooting sequence is what I'd do (which is similar, no matter what the type of computer):
1: Do the fans spin up if you turn it on?
No: Power supply issue (or connections to power supply, fuse inside the power supply, etc.)
Yes: Move to the next step.
2. If you have one of those tiny PC speakers for mainboard "beeps" connect it (J7 - SPK. That's the long single row of pins next to the bottom ISA slot. It's the 4 pins on the right side (should say SPK). What kinds of beeps do you hear when you power on the computer?
1. Short "bleep": Memory likely OK
2. Long "beeeeeeeep - beeeeeep - beeeeep" memory likely bad
3. Move the video card to a different PCI slot and turn on again. Do you see the RAM counting up now, etc?
Yes: Clean the video card contacts and the PCI slot. Or just leave the video card in the other PCI slot. You might have to make IRQ setting changes in he BIOS to avoid issues, though.
No. Move on to the next step.
4. Do you have a PCI video card lying around (doesn't matter what brand/model)? If so, install it and turn on. Do you see the RAM counting up now, etc.?
Yes: The original video card was the problem and you need a replacement (a random different one won't let you boot fully).
No: There's still a different problem (might be RAM or the mainboard).
5. Remove all the cards from the mainboard, except for the video card. Disconnect everything else, except for the video card/monitor, computer keyboard and power. Turn on again. Does the RAM count up now?
...... etc. etc.
You see where I'm going with this. Just a systematic process of elimination. Of course you need some spare parts to be able to do this (RAM... which you have now, PCI video card, maybe one of those little computer speakers that connects to the pins of the mainboard, etc.). I have all that stuff, and that's why I was offering to help. But the above is what I'd do... maybe followed by cleaning up all the contacts on the mainboard, while looking for burned looking components... and if nothing looks odd, I'd try to swap the processor next, or the entire mainboard (depending on what spares you have, or how much you're willing to spend on spares).
Anyway... all you need to understand for troubleshooting stuff like that, is the "process of elimination", and a little bit of signal flow understanding (not just for audio, but also how electricity travels between components). Then you should be able to pin it down...
Good luck.