Bad BIOS

[Roofer]

Can anyone help please. Every time I start my PC It comes up with the message :- Bad BIOS Checksum and then trys to read from CD or floppy.

The only option is to keep restarting the PC maybe 4 or 5 (or more) times until eventually it appears to be starting normally but takes me to a check page which basically tells me that the CMOS Checksum is bad and the CMOS Date/Time is not set.

Despite setting (and saving) the date and time the PC will still not start properly next time and I have to go through the whole process again. It's very, very irritating.

Has anyone got any thoughts on this,

Thanks

 

[JohnD]

How old is the PC?

 

[Roofer]

Just over 2 years old. It's a Mesh and up to recently has been no problem at all, except the noisy fan but that's a problem for some other time

 

[nstreet]

Borrow a friends pc and download the latest bios, it should allow you to put it on a floppy disk. You then boot the machine with the disk and it will re-flash the bios. Make sure the battery on the motherboard is ok and check the seating of all components.

 

[Roofer]

Thanks nstreet, it is most likely to be the battery?

I have a laptop but what do you mean about downloading the bios, where from?

Thanks

 

[JohnD]

(I was thinking that, if old, the battery on the motherboard might be going flat, but 2 years is not long. the battery will probably be about the size of a 5p or 10p piece, make sure it is firmly seated and no sign of corrosion or bad contacts round it.

If you press "delete" repeatedly during boot up you might have an option that shows you condition of battery, and another that will enable you to reset to factory settings or to optimum settings, you could do that if you feel confident about changing settings afterwards and have the motherboard manual

 

[nstreet]

Thanks nstreet, it is most likely to be the battery?

I have a laptop but what do you mean about downloading the bios, where from?

Thanks

When you boot the pc, when the screen is first displayed it normally has the name of the bios manufacturer and the version (AMI, Award etc etc). Search for bios manufacturers website via google. here's the Mesh site, a good starting place. http://www.meshcomputers.com/Default.aspx?PAGE=RUNTIME_OLD_SUPPORT_HOME

 

[gcol]

There should be a set of jumpers on the motherbaord that'll allow you to reset the CMOS. It should say CMOS beside it. If you can't see it check with the manual for CMOS jumpers.
All you need to do is move the shorting link from the position it's in to the next position to short those 2 pins out, then move it back to where it was.
i.e. from (o o o) to (o o o)
That should reset you CMOS and hopefully solve your problem.

 

[Roofer]

Thanks all,

I think I'll replace the battery, see if that cures it and then take it from there

 

[gcol]

Betcha the battery isn't flat - Lithium batteries on motherboards genreally last a lot longer than 2 years.
However, removing the battery for a while has the same effect as resetting the CMOS with the jumper. So you might still fix it that way anyway.