checksum bad error

**sayeed** · 11-02-2009

Hello to the experts

here is my configuration first:
Pentium 4 socket 478
ASRock Motherboard + P4S55FX
1G RAM
Hitachi hdd 180
Geforce 5100
No internet connection

following that I had a serious crash of the windows OS and a serious desire to revitalize the system, so I decided to format and re-install the windows except that ... it was impossible to achieve a result, I will explain:

1) If I install windows and the first boot when I'm on the screen of the Windows desktop system hangs
2) there is always a moment during the installation of the screen is frozen
3) boot and it is a message I CMOs / GPNV checksum Bad
4) the screen I see has no video input
5) also impossible to access the bios setup but can choose the boot screen

So I searched a lot on the net for bad checksum and was told we had to change the battery on the CMOS which I did but there was no result above except that of CMOS / Bad checksum GPNV I passed checksum bad.
I tried to install other OS Ubuntu, Kubuntu but no results
I tested all my hardware and everything works separately no error bars in the RAM, low-level formatting ..

I hope someone can help me solve this problem and I thank you in advance

**nitesh mehta** · 11-02-2009

first off swap memory with a different module (true this is highly unlikely) but its fast and quick and fairly easy to do. ditto the cmos battery next try to do a tattoo on the board if not check/reseat any socketed chips on the board. did you have this error before you did the upgrade?

**JAMES_911** · 11-02-2009

The CMOS Checksum Bad Error is an error that occurs when the CMOS values are incorrect. Usually to guard your Bios software, your CMOS memory stores a specific value, each time you boot up your computer this value which is a number is checked against the stored value in the CMOS memory. If these two values are different, it causes an error message. If these values are the same, the computer proceeds as normal.

Each computer usually deals with the CMOS Checksum Bad Error differently. Some computers will warn the end user and continue to boot up using settings in the CMOS, other computers might warn the end user and then use the default settings in the BIOS as the correct settings and carry on with a normal boot or reboot. Usually, within the error message it will state which strategy your computer has employed.

If you have encountered this error and would like to fix your computer, here are some remedies for each situation:

CMOS Battery Not Functioning Properly: If you suspect your CMOS battery is not functioning properly you can easily change it. Before changing your battery, reboot your computer to make sure that the error still exists. If it does, go into your CMOS and write down all of the settings. If all settings are lost, you can usually get them from your computer manufacturer. Now locate the battery and remove it, you might need to consult your computers manual or tech support to remove your battery. Take down the CMOS batteries information such as volt, size, etc. Once you have your new battery, you can replace it and reenter your CMOS settings. If your battery was the cause of the CMOS Checksum Bad Error, you should have remedied the problem.

Your BIOS has Been Updated (either by you or possibly a virus): If your BIOS has been updated recently, your CMOS settings may have become reset. Make sure that the values entered in the BIOS are correct or simply reset them to the default settings. If you believe that a virus updated your BIOS settings, run a virus scan and make sure that the BIOS settings are back to the default.

The Computer Was Shut Down Improperly: Sometimes when running MS Windows, if you shut down your laptop or desktop without first properly shutting down your operating system it will corrupt the CMOS settings causing the CMOS Checksum Bad Error. You can easily avoid this error by making sure that you completely shut down your computer before turning off the power. Usually this entails going into the Start Menu/ Turn Off Computer/ Shut Down. If you received the error, shut down the computer properly, if this is the cause of the error, the error message will not return.

SourcE: tech-faq.com

**newtech** · 11-02-2009

A CMOS check sum error is usually caused by corrupted data in the CMOS memory. When the computer boots it adds all of the ones and zeros in the CMOS and drops the carry bit. It compares the resulting sum to a like (we hope) sum that was generated when the CMOS data was produced. If the two do not match, the CMOS is presumed corrupted, and an error is generated. The corruption can be caused by defective CMOS memory or power problems caused by a shorted motherboard, an expansion card that is not properly seated, a defective component, etc. I would check the battery with a multimeter and make sure it is good and installed correctly. Some older motherboards have a CMOS battery soldered onto the motherboard and have a jumper which must be changed to use an external battery. The battery on the motherboard should be removed if an external battery is installed. It can leak and damage the motherboard beyond repair. Do not use a soldering iron or anything hot to remove a battery form a motherboard. The battery can explode. I use a combination of pliers and diagonal cutters to remove these batteries. The computer must be unplugged when doing it and care must be employed (not an operation for an overly ambitious gorilla). Some batteries include the system clock, are usually black and rectangular, soldered to the motherboard, and are supposed to have a 10 year or greater lifetime. When they fail, the motherboard is usually a goner. Most motherboards have a jumper, which can be used to discharge (erase) the CMOS memory, and this may fix the problem. Be sure the computer is off and unplugged, move the jumper to the discharge position, wait 10 minutes, move it to the normal position, attach the power cord, and turn-on your computer. Some motherboards can be damaged it the computer is powered on with the jumper in the discharge position.