A7N8X Deluxe will not post

[Mitch]

I have an A7N8X Deluxe that has been running solid for a long time. Now
when I save to BIOS it will not POST. To recover I have to Clear BIOS.
Once I clear BIOS everything works fine but I cannot change my BIOS anymore.
When I do an EXIT and Save in the bios, the screen goes blank, the fans
continue to run, and the power on light remains on but it never posts, it
just sits there with a blank screen. I then power down, unplug, clear BIOS,
plug back in, and turn it on. It then POSTs with an error message "CMOS
checksum error - Defaults loaded" It resets the system Bus to 100, even
though I have an AMD 2800 that runs at 166. I press "F1" and it boots
normally, with Windows 2000. I can change the date and time in WIndows and
this seems to work. I can enter the BIOS and exit without saving and that
has no problems. As soon as I save in BIOS, I cannot POST anymore until I
clear CMOS.

Has anyone else had problems saving BIOS?

- Mitch

 

[TomC]

Mitch;

OK, I will ask the obvious question:
You did return the mobo jumper that clears your CMOS to the correct position
after clearing, right?
I'm not sure if the A7N8X Deluxe is the same as the A7N8X-e Deluxe, but if
so this is the CLRTC1 jumper in line with the middle PCI slot, jumper should
be on pins 1-2 during normal operation.

Tom

 

[Charles]

when you take the BIOS jumper off, leave it off for a few minutes before
replacing; sometimes the power decoupling capacitors can hold enough charge
to keep the CMOS chip going for quite a while, this happened to me a few
years ago

 

[Mitch]

I am pretty sure I am clearing CMOS properly because that is the only thing
that works. After I clear CMOS, The computer POSTs and works perfectly.
The problem is when I do not clear CMOS. If I save my BIOS, the computer
will not POST anymore. This happens even if I do not change BIOS. Just be
entering BIOS, then doing an Exit with Save, I cannot POST anymore. The
only way I can POST is by clearing the CMOS. Once a clear CMOS, then it
POSTs fine but the FSB is set to 100 when I clear BIOS. I am unable to get
the FSB to 166.

- Mitch

 

[aberger]

Try changing the back-up battery.

Arnie

 

[Vince]

Mitch, a couple of months ago I posted here with the exact same
problem that you describe. I decided to re-assemble the system one
step at a time, first removing the mobo and connecting to the power
supply outside the case, with just the video card, mouse, kbd and
monitor connected.

Eventually, one step at a time, everything was put back together
and the problem disappeared. I *suspect*, since originally I didn't
have a screw in every metal spacer supporting the mobo in the
case, that an intermittant ground contact between the mobo and the
chassis may have been causing the flaky behavior. I don't know
for certain. But I *do* know that after following this procedure my
BIOS save problems went away and my system has been rock-solid,
ever since.

It's a bitch to have to go through disassembly and re-assembly,
but sometimes it does the trick.

 

[Paul D. Motzenbecker, Jr.]

Vince et al:
Greetings and hallucinations from just north of Fantasy Land (Washington,
DC)!
This is old hat in the computer industry. One thing, however, Vince, it
would not have been a bad ground. There is also a ground supply in the main
ATX connector. The host of things that can go wrong is legion with these
computers.
Peace,
Paul

 

[x]

Maybe the bios is corrupted, can you upgrade to a newer bios or write the
same bios over again?

 

[Mitch]

I have reflashed my BIOS with the most current BIOS and it has no impact. I
can enter BIOS and everything looks ok. If I exit BIOS and DO NOT save,
everything is ok. If I do not change BIOS, but EXIT AND SAVE, I cannot post
anymore until I again clear CMOS.
- Mitch