ASUS X51R Notebook

[Numan]

Hi Motherboards.org,

I have an ASUS X51R Notebook all of a sudden it is having trouble booting up, I'm usually looking at a black screen.

But sometimes I get a bit further and we get a message like:

CMOS CHECKSUM BAD
SET TIME/ DATE

But when we try to enter the BIOS we are prompted for a password that
we did not set.

I've tried removing the battery and mains power and pressing the on/off button for 45 seconds. But now I get the message:

CMOS battery low
Press F2 to resume

after I press F2 I'm prompted for the password again.

Is there anyway of flashing the BIOS in this situation?


Please can you help me?

Regards
Numan

[evasive]

CMOS battery low

means you need to replace the battery with a brand new fresh one. That should get the laptop back to normal working order.

[Numan]

Are you sure?

The Notebook is 2.5 years old, and not used very often.

I think what has happened is that the notebook runs on mains power (no battery inserted) and was unplugged before windows shut down properly (maybe installing updates). I'm not 100% sure of this but it is what I suspect.

[fussnfeathers]

CMOS batteries only last a couple of years under normal usage. Three, tops, although I do have a couple of boards five years old or more that are fine.

[Copper]

the cmos battery is seperate battery from the main battery, and they only last for about 2 - 3 years

[Numan]

Hi,

I've replaced the CMOS battery, but the problem persists. Anybody got ideas for me to try before I send the notebook back to ASUS?

[mau29]

Hi Neuman, I have the same problem here... did you resolved it?

[Numan]

No. Not yet I'm saving up to send it back to ASUS. They think it might need the motherboard replaced, which could cost about £200.

[Copper]

No. Not yet I'm saving up to send it back to ASUS. They think it might need the motherboard replaced, which could cost about £200.

take it to your local repair shop, and get a quote from them, spending £200 with asus is over the top, compared with the price of a new laptop from someone like Tesco that sell laptops from about £260

[Karlsweldt]

The BIOS battery is a backup for desktop computers, used only when the mains power does not enter the PSU. With laptops, it is in use more frequently, and may last only two years or so. Once the battery is replaced, you have to reset all the BIOS pages to reflect the true system setup.
That "CMOS checksum error" message is a general warning that something is mismatched between BIOS settings and actual hardware. Could be any one of more than 20 features.