"I have no way of entering the BIOS to change settings ..."
Why? KB faulty? Don't know the key combo to press? No reaction to correct keypress?

I think accessing setup should be item #1 here. Once inside try setting "Factory default" or similar. Save and
reboot.

Also, you may have a cabling fault here. Try starting with all cables removed and see if you get a clean POST.

/RID

Hey bro, to give you some light on the problem:

a) Put the mobo with only the VGA, processor and memory on it. If the message is still show put them on a new mobo. This won't break again. If the message is still showing you can be sure that the problem has nothing to do with virus. Maybe the ROM Checksum fail is about the VGA not the BIOS.

b) Then replace the VGA for a new one, maybe the problem is here.

c) Also replace the PSU. When they fail strange things happens.

Give the feedback about what I tell you and then we wil continue.

SoMoS

Disconnect the diskette drive cable. Does the problem still happen? I guess you may have the cable upside down.

http://search.experts-exchange.com/Hardware/search.jsp?query=BIOS+ROM+Checksum+error+&searchType=topic&questionsAskedWithin=anytime

i am not sure if you can access above url...see if this helps...

else see this...your processor could be dying

First, the BIOS is not dead nor corrupted.  The BIOS ran and reported error.
2nd, the CPU is not dead either because it ran the BIOS code.
3rd, BIOS will report checksum error whenever you change configuration - RAM - video, etc.... it's normal.
----, its BIOS way to let you know that something has changed
Check your cable first:
4th, the solid light on the floppy - the most likely thing is you reversed the ribbon data cable.....
----, the ribbon data cable has a color strand on one side - that is pin 1.....
----, pin 1 side should match up with pin 1 on the motherboard connector (it's marked with number 1)
----, pin 1 side should match up with the floppy - it's marked - pin 1 is 99.9% of the time is next to the power connector
5th, the solid light on the drive - two things:  you connected the drive light cable incorrectly on the MB.
----, you may have reversed the ribbon data cable - if you did you may have wiped out the drive or its MBR already
----, may be that's why it's asking for a bootable diskette
----, use the same procedure as the floppy to reconnect the HD
Second step:
6th, most bios use the DEL or one of the PF key to enter into the BIOS either F1, F2 or F12
----, few other bios uses ctrl-end, esc, alt-esc, etc... combination to get into the BIOS
----, once you get into the BIOS - it will recalculate the checksum and rewrite it when you exit and save the BIOS
----, you can try new motherboard as you have done - you will get the checksum error until you entered into the
----, bios, configure it and save it  - <BOLD>THIS SHOULD<BOLD> be your next step -
Last:
Boot up the system - and hope you didn't wipe out the hard drive.....
if you did - before you repartition and reinstall - boot up a DOS diskette with the sys.com or sys.exe on it....
run the command sys C: from the DOS prompt - reboot the system to see if the HD is OK.....
if the HD is not OK - it's time to repartition-reformat-reinstall.....
 

..another confused person about bios and cmos
1. First, the BIOS is not dead nor corrupted.  The BIOS ran and reported error.
it requires very minimal code and cpu efforts to run the checksum code, it is usually kept at the begining of the bios startup....bios has indeed run, but it also checks the remaing and critical code to see if it has errors. if it has, it just gives the error.

2nd, the CPU is not dead either because it ran the BIOS code.
booting with cpu is not a foolproof test...you will learn this by experience...

3rd, BIOS will report checksum error whenever you change configuration - RAM - video, etc.... it's normal.

that is "CMOS checksum error",
bios = boot code that does the configuration, startup checks etc
CMOS = small part of memory where bios code stores config data

I have already thought of the cables being in the wrong way into the floppy and HDD but have already been checked out OK.

Things that have already been replaced are: VGA card, PSU, Processor, RAM, M/B, IDE cables.

"Why? KB faulty? Don't know the key combo to press? No reaction to correct keypress?"
I know how to enter the BIOS and would do if the machine got far enough

In essence it is a completely new PC. I have tried disconneting all peripherals just leaving PSU, M/B, RAM, CPU and VGA card connected. The same message still appears.

Kiranghag, I read one of your solutions a while back involving the same error and it seemed that replacing the M/B worked for the guys computer, is it possible that the BIOS chip could be at fault on a new motherboard? Also, why would I need to flash a new BIOS chip? If I need to, the chip hasn't got a silver sticker to wipe it, am I right in guessing I need software to flash the chip and if so how would i run the software with my current problem?

Well at least i'm getting paid for this so i'll see what happens today

Cheers
Pyro

SUCCESS!!!!!

Pulled the old mobo out of the bin, took the BIOS chip from that and whacked it on new mobo, presto!

There must have been some power surge that fried everything, hence the reason I had to replace almost everything, when i put the new mobo on that same something must have fried the BIOS chip straight away.

Ears have stopped smoking now

Thanks a million

Pyro

this swap should work only if the mobos are identical...
since u said that things are working fine...no probs...just enjoy...