# CMOS checksum error on loading - no keyboard??



## Chris231218 (Jun 5, 2009)

Hi,

I have been given a friends pc to repair but I'm stumped straight away.

On booting the pc, I get the error message" CMOS Checksum Error - Defaults Loaded. Press F1 or Del"

Unfortunately the PS2 keyboard is non-responsive and I cannot press F1 to get any further.

I have tried swapping keyboards, using a USB keyboard and swapping the mouse and keyboard around but to no avail.

So far I have replaced the battery on the motherboard (Abit KT7E) but this does not make a difference and also removing all other components to no avail.

I know there is power to the keyboard cos the lights flash when the pc is first turned on, also when I swapped with my infa-red mouse there was power to the mouse.

The pc is running XP and I appreciate it is an old motherboard and system but none of us like to be beaten so any advice will be much appreciated.

Thanks

Chris


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## Tyree (May 10, 2009)

PC Specs?
Pre-Built Brand & Model Number
Custom Built-Brand & Model of Mobo-CPU-RAM-Graphics-PSU.


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## Horusrogue (Aug 31, 2009)

Did he attempt to update the bios at all in the past while before giving it to you?


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## Chris231218 (Jun 5, 2009)

Sorry, the motherboard is an ABIT-KT7E, its not brand built so has no model number. It has 64MB Ram and is running XP Pro Home Edition.
Apparently he gave it someone else prior to myself and got it back in this state.
To be honest my guess is the mobo has had it but as I stated I dont want to be beaten!!


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## Tyree (May 10, 2009)

We need to know the system specs, as requested in my Post #2, to offer and reliable suggestions.
Is there a Mobo speaker? 
Do you get any beep codes? 
Do you get any beep code swith no RAM installed?


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## Chris231218 (Jun 5, 2009)

I have no beeps on start up, I dont believe there is a mobo speaker.
I have exchanged all of the 3 rams and run it with none in but it makes no difference.
Sorry if I am being vague please continue with your help its much appreciate.


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## dai (Jul 2, 2004)

specs

you can see the computer 

we only see what you post

checksum error usually comes back to insufficient power


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## Chris231218 (Jun 5, 2009)

Ok guys, so lets look at it from a different angle...

Why has the mouse and keyboard stopped working? If the keyboard worked then I could press F1 and sort the BIOS out


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## Horusrogue (Aug 31, 2009)

Chris231218 said:


> Ok guys, so lets look at it from a different angle...
> 
> Why has the mouse and keyboard stopped working? If the keyboard worked then I could press F1 and sort the BIOS out


Test with a different power supply. One known to work or borrow a working one for a couple hours. 

Have you benched the system as per the forum definition? *(Can someone repost it?)*

*Wait it runs 64 mb of ram? Good lord. lol. Try to find some 128mb sticks around or something. Three rams? What are they??!?!?! How did you get three sticks to add up to 64 mb?*


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## Tyree (May 10, 2009)

Tyree said:


> PC Specs?
> Pre-Built Brand & Model Number
> Custom Built-Brand & Model of Mobo-CPU-RAM-Graphics-PSU.


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## Chris231218 (Jun 5, 2009)

Sorry guys does this help...
Mobo - Abit KT7E
Processor AMD Athlon 900Mhz
RAM 768MB (3x256)
nVida FX5200 AGP8X
300W Power Supply
Windows XP Pro
I have no idea who built it as it is not a pre-built brand

I have done the following -
Power supply changed
Removed and tested all RAM individually
Changed CMOS battery for a new one. Reset jumper.
Tried new PS2 keyboard, tried USB keyboard
Swapped mouse and keyboard ports
Unplugged CD drive/floppy drive

I still get no keyboard response full stop.
System says CMOS Checksum error - defaults loaded - Press F1 or DEL
I cannot do either
Ran with no RAM (Got beeps and did not fire up)


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## dai (Jul 2, 2004)

check for bad caps

http://www.google.com/url?sa=t&rct=...9f3VBg&usg=AFQjCNGJO7OVF36bXyFYiZ1m3otHk3LehA


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