0251: Stsyem CMOS checksum bad...

[VannaB]

Help!
For no apparent reason my computer no longer starts up properly. When I switch it on at the plug I then usually need to press the button on the tower to switch it on, but now when I flick the mains switch it powers up itself and then I get a black screen with the following on it...(I've missed some bits out)
Mouse Initializer-ERROR
Date and Time ERROR

0251: system CMOS checksum bad

As it loads up the hardrive appears to make a grinding noise as if it is searching for a disk to load? Then when I press the f1 button it then loads and I have to reset the time and date.

Why is it doing this and can I ask someone to help me sort out the problem if it can be solved? My computer is 5 years old now so a bit of a dinsoaur! Thanks!

[bekka]

Most probably a dead or drained CMOS battery...cheap enough and easy to replace.

[bekka]

Do you have the manual...if not what computer do you have...

Manuals can usually be downloaded and contain a check list of what cause certain faults and recommended fixes.

[VannaB]

Thanks but what is a CMOS batterie then? ANd where would I get one from and where does it go?

[bekka]

What computer is it?

[bekka]

Quicker and more explanatory than i can do is here.

http://www.liverepair.com/encyclopedia/article s/cmosreplace.asp

[ACtheTROLL]

make sure your little pinkies are spotless before you touch the battery (even better hold in a small CLEAN smooth cotton cloth

also make sure you are in contact with the case which you have UNPLUGGED when you do the business to reduce static.

the bad news is that in many (not all) older boards (and if the battery is dead - it must be older) the battery is welded to the tags which are soldered to the mobo.

if it's not at least 5 years old I'd be concerned something else was wrong

[VannaB]

It's an E-Machines 370 desktop. I'll try what you suggest although I've never tinkered with my computer before so wish me luck and I'll let you know the outcome!

[bekka]

If you have a PC repair shop near you why not pop in and ask for an estimate on replacing the CMOS...it may not be the fault but the symptons do point to it.

[ACtheTROLL]

I'm with bekka on this one

even when the battery is dead ...if the machine is used reasonably regularly ... you will normally at least get a startup

lappys often use standard button batteries ... but in my experience most desktops use removables
I have changed a couple of batteries - out of badness .... but it's a big job - requires removal of the mobo .... and use of a thermo soldering iron - and strong reading glasses!!!!