Had this ghost in my machine 2 years ago. Would restart, shutdown or just go straight to full off without warning. It would also hang up on restart or startup. Most of the time it got to the HD and stopped booting.
I cleaned everthing including removing the processor and putting on new cooling paste. Checked every connection, checked voltages and replaced the RAM(wanted to double it anyway). Put the HD in another rig and it seemed to work fine. Used the other rig to scan for virus/spyware/malware.
Then out of frustration I b'slaped it on it's right side real good. I come right out of hybernation-not boot. Been fine for 2 years. My guess is it had poor continuity at a connection somewhere and I missed it.
What I would try first:
Check power suppy. Check all connections. This includes power and com plugs and board sockets. Take apart anything that you can. Even network or modem cards. Any weak connection could be a power drain or com distress.
Pay paticular attention to the points of contact on boards for discoloration as if some of them have gotten hot. Check the pins in connectors to see if one is recessed farther than the others.
When reconnecting try to install cards evenly and firmly. Watch all the wires at connectors to see if one backs out as it's going togeather. Gently push each wire that you can get your fingers on toward the connector just to be sure.
Second: Check what you can with another computer. Drives don't have to be physicly installed, just the power and coms. I even tested the dialup modum in with a old computer. If you RAM will interchange with another rig, test it too
Third:
Bypass what you can. If you can switch video to AVG do so in you Bios. (Check me if I'm wrong, but I believe the boot process is handeled through AVG and not advaced graphics). I say this because Zone Zero may stop the boot because it detects a problem elsewhere-such as your vid card(again, someone check me on this). If you have more than one vid output, hook monitor to the one on the mother board.
Also change the boot order to try HD first if you can in you Bios. Remove any card that are not nessisary for basic computing. Unplug all other drives.
If you cannot change boot order in Bios I THINK zone zero will skip to what's available (check please). I also think that a virus that turns zone zero into the "dead zone" will not even allow it to check for drives- so if it checks for one, that's not the problem(check me one more time).
If you have more than one stick of RAM try it with only one and change them out each try. Make sure it is enough to run on first.
Forth: Smack the crap out of it.
I know it's a lot of work but without AH to play, you may have some free time. And good luck.
