Returning a intermittant faulty motherboard

  hat.stand 13:41 22 Oct 2009


I'm hoping for some advice on the return of faulty good - hopefully someone might know more about this than me.

After about 3 months use it came up with Checksum error and I replaced the battery.

This worked fine for a month or two and then the checksum error returned, and I could not get past it - I reset the bios a few times and could not boot the machine.

I returned the board back to scan - but they say they can find no fault with the board and wont replace it unless they can.

Can they do this? I've not way of showing them the fault on my system and they flatly refuse to replace it unless they can replicate it.

I believe this fault is intermittent - there is nothing I can do to make it happen for them...

  OTT_Buzzard 14:18 22 Oct 2009

When does the checksum error occur?

It couold be a number of things, including the motherboard, but also the graphics card, processor and RAM...and probably more besides!

  hat.stand 14:42 22 Oct 2009

On startup.


1. Power on
2. Screen bios startup screen shows whats connected to the computer (the usual screen you see when first turning on a computer)
3. Checksum error appears

I'm sure this is the BIOS as it asks me if I want to reset to defaults to enter setup.

How could the ram or processor cause a checksum error?

  T0SH 12:26 23 Oct 2009

A CMOS checksum error simply indicates that a the BIOS has detected that the setup settings data has changed for some reason, this data is stored in an area of battery backup ram which is part of the real time clock device on your motherboard

The prompt is not always the same but mostly it says "Press F1 to continue or F2 to enter setup"

To clear this error choose F2 to enter BIOS setup do not make any changes use either F10 or use the arrow keys to move to the exit option and choose to "save settings and exit" (again this prompt can vary depending on BIOS types)

On your previous battery replacement it would not be unheared of for a replacement CMOS battery to be faulty or even past its use by date which is often just a meaningless code on the packaging rather than an actual date

But whatever if it only happens on an odd occasion it probably does not indicate a motherboard fault

cheers HC

  hat.stand 12:29 23 Oct 2009

Thanks for your reply.

The final time it happened I could not get it to continue - I reset the BIOS, saved it and the machine rebooted - then checksum error again.

The machine has on board graphics - so assuming theres no problem with that what else could cause the error?

  T0SH 17:08 25 Oct 2009

Are you 100% sure that you did replace the battery with the new one ?

I have come accross more than one occasion where people have removed the old battery placed it on the table or the floor where they were working unpacked the new battery put it down in the same area then promptly installed the old battery and thrown the new one and the packaging in the bin

As I said previously the only thing that brings up the checksum error you are getting is a loss/corruption of the data due to the battery losing voltage as it discharges over time

Does this happen if you power down for a few minutes or does it only occur during overnight shutdowns ?

you could also try using hibernation instead of shutting down your computer overnight do this for a week or so to see if the problem happens then

Cheers HC

  hat.stand 09:12 26 Oct 2009

Well the buggers have returned the board back to me.

I've rebuilt the machine and installed Win7 on it to see what happens.

Its booting perfectly at the moment and so I'll have to wait and see if the checksum error comes back.

Thanks for your help.

  bjh 09:24 26 Oct 2009

If it does, take a digital photo of the error on-screen, open the case, take a series of photos of the assembly, and then return the board with this as some form of back-up evidence....

Hopefully the fault has gone - for whatever reason!

Best of luck - I know how frustrating an intermittent error can be!

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