I've screwed up BIOS

[schultzm]

I have AMI BIOS 1.21.10 and I accidentally disabled 32Mb of shared memory (presumably used for video memory). The PC will not boot and I get no video output.

I cannot identify the manufacturer of the motherboard easily - would anyone be able to tell me if it is possible to reset the BIOS to factory settings so that it does boot.

[Budfred]

There are two main ways to do that. The easiest is to pull the Clear CMOS jumper from the two pins it is on and place it on the middle and end pin. Pull it again and put it back of the first two pins. If you have the motherboard manual, it will tell you where to find it. Do all of this with the power off.

The second method involves removing the battery on the motherboard. Unplug the computer, pull the battery, push the power-on button and release it. Wait about 30 minutes, put the battery back on the motherboard and plug the computer back in. See if it will boot and post back here if it doesn't....

[schultzm]

Thanks - I found the jumper and reset the BIOS successfully.

The real problem I am trying to sort out is the stability of the system. I think that the memory may have errors so I ran memtest86 - this showed errors in the first 14M of the 1st bank of 128Mb RAM. On swaping the two banks over the error moved to 142Mb. Okay I thought replace one of the 128Mb DIMMs. Then I removed the "faulty" DIMM to boot with just 128Mb and the previously good DIMM started to report errors at 14Mb. On replacing the bad DIMM the error at 14Mb disappeared?

Any ideas appreciated.

[Deagle]

I'm not really sure what you've said there but errors from running memtest86 doesn't necessarily means you have an unstable system. That program is just for overclocking enthusiasts to see how much more they can push their system(or ram at least).
:cool:

[schultzm]

So can you suggest any other memory test software.

What I failed to mention is that the POST test also claps out at 140Mb.

[Deagle]

I suppose you have ddram but you didn't tell us the speed/brand. For ram testing you can try sisoft sandra's burn-in test.

[schultzm]

The memory is 1 off PC100/128Mb and 1 off PC133/128Mb. The BIOS is set for 100MHz memory access.

The POST test detects an error with the PC100/128Mb module when both modules are present in the motherboard. However, if this module is removed the PC133/128Mb module which passed the POST preeviously similarly errors.

My gut feeling is that I should replace the PC100/128Mb with a second PC133/128Mb.

On the other hand I don't have much confidence in the motherboard.

[Fruss Tray Ted]

Though it sounds as if both memory sticks are bad, replacing a pc100 with pc133 is not always the answer. If I recall correctly, some pc100 RAM boards require ECC type memory and you should look into what your mobo requires before installing/purchasing another stick.

System specs would help. ;)

Have you tried a new battery?

[Budfred]

Deagle,

I'm not really sure what you've said there but errors from running memtest86 doesn't necessarily means you have an unstable system. That program is just for overclocking enthusiasts to see how much more they can push their system(or ram at least).

I am not sure where you heard this, but many of us use this and DocMem for conventional testing, not just for overclocking. Do you have any info to support that statement???