Abit NF7-S v2.0 Mobo/BIOS gone bad?

[phlashphire]

System:
Abit NF7-s v2.0 with mobile 2400+ oc'ed to 3200+ at 1.8V
2 hd's, one 200gb sata Seagate, one 80gb Maxtor
2 120mm fans and one 92mm fan on hsf
DVD-RW
Floppy drive
SB Audigy
2 sticks of 512mb RAM
ATI 9800 Pro oc'd to XT w/ Arctic Silencer
Antec Neopower PSU

The system listed above has been running fine for a while now, just last week I added a WD 36gb Raptor to my system, after formating and rebooting it gets stuck at the BIOS screen showing press "Delete key" to go into BIOS settings. Pressing delete, non-responsive. Powered off completely, turn off PSU, powered back on and same thing.

Next I powered off and cleared the CMOS with jumper, boot up, this time responds to 'del' and goes into BIOS. I make my changes, (200 fsb, VCore upped to 1.8, disabling on-board sound & network, etc) save and exit. Boots into windows fine. Run couple of quick tests and benchmarks, all looks ok and then power off.

Power on, again, it's hung at the BIOS screen... again have to power off and clear CMOS.

Things I've tried so far:
1. Removed the new 36gb drive, going back to original config
2. Tried flashing to different BIOS' (currently using ABIT-NF7D26-MantaRaysXT-2T)
3. Replaced CMOS battery

Temperatures are still good. Voltage readings on psu still stable and solid.

 

[Noid]

Flash to ABIT BIOS
(go back to the mod BIOS later)
See if problem still there ...

If Yes ... keep ABIT BIOS

Pull everything non-essential ...

Use 1 HD
One stick of RAM

Remove SC, floppy,, extra HD's etc ...

Be sure to use Default FSB and multi ... etc ...

See if problem still there ...

... your gonna have to put your 'thinking cap' on ...

Use process of elimination

 

[phlashphire]

Thanks for the suggestions. Just tried them, and no go.
Tried the official ABIT last BIOS ver nf7d27, still same problem. Lowered to default FSB (no overclock) to 1800Mhz.
Even tried tried changing the "System BIOS Cacheable" (whatever that does) in the BIOS options. I'm almost sure that I can eliminate the BIOS versions out of this as I have tried the official BIOS and several Mod BIOS, all yielding same result.

It's something related to the mobo and powering down. Only other thing I can think of is the power supply.
I'm not even sure where to look anymore, maybe I should just leave the pc on from now on... :frown:

Anyone know specifics about BIOS chips or other on-board elements that can cause this type of problem?

 

[Noid]

I had that problem with MSI K7master...

But, that was a known issue... And the only fix was to ...

Flip switch off on PS.
Pull the plug from the PS, count 22 seconds, plug back in....

then powerup

I have no idea whats up with your problem ...

How far thru the BIOS bootup diagnostics before you error ...?
When you get a clean boot ... are there unidentified devices in Device Manager ...?

Maybe APIC is messed up ...?

Have you tried a different CPU ...?

Is CMOS battery OK ...?