ASUS A8N5X - not accepting kb input during POST

Got a very strange problem here. For whatever reason, during POST, keyboard input is not recognized. POST hangs up for a few seconds after it detects the chipset as well. I get a single POST beep indicating everything's ok...

I pulled the CMOS battery for several minutes and ran the system during this time with the battery pulled. Still wouldn't accept input...then it gave me the "CMOS checksum failed - F1 to continue" message (of course since my cmos was pulled), but of course F1 didn't work...interestingly enough. if I press and hold that button right when the computer starts up, it will go through (so at some point it's somehow holding onto the keyboard longer up to that point).

Same thing with getting into bios setup. If I try pressing delete key during post, it won't work and not enter setup. However, if I hold the del key right after I power the system on (before display turns on), it'll go to the setup screen...but then nothing will work beyond it (setup menu's there, but keyboard no worky).

I have absoltuely no idea what's going on here. After POST, and GRUB (bootloader) loads, keyboard works just fine. Gentoo loads up, everything's peachy keen. It's not an issue with the kb or mouse, as I've tried others as well. Both USB and PS/2 keyboards have the same symptoms. I've basically done all the troubleshooting I can think of :\

I left the power unplugged overnight and it didn't help any. I tried updating my BIOS but it fails whenever the flash is being verified...but it succeeds if I flash it with a backup copy of the old BIOS that was created off the flash chip before I tried updating.

Meh

 

Anyone?

 

What kind of keyboard? PS/2 or USB?

If it is a PS/2 keyboard, I've noticed if your pressing the delete key a bunch of times during the POST, the keyboard will become non-responsive, on certian boards and certian BIOS. Instead, press the DEL key only a few times.

If it is a USB keyboard, could be an issue with the keyboard and that particular boards BIOS, try a different keyboard.

Also when reseting the BIOS, instead of removing the CMOS battery, move the BIOS reset jumper, usually near the CMOS battery. To do this, first, power off the computer, move the jumper, and press the power button on the computer. The computer (usually) will not power. After you do this, move the jumper back and your BIOS will be reset.

If nothing seems to work, try another keyboard, or different type of keyboard (PS/2 - USB)

 

Thanks for the BIOS jumper advice. That helped me restore keybord input, and I was able to further troubleshoot what was going on once I got into BIOS. It seems that my stable overclock that's ran for 2 years is no longer holding its stability anymore, kb input becomes sporadic again once I begin overclocking, so now I have everything at factory default

 

Overclocking can be "dangerous." I would nto reccomend overclocking for long periods of time (although I'm guilty of it myself... kind of goes with that saying, do as we say not as we do )