Cmos checksum failure 1

[hylux82]

Hi anyone,
I have just rebuilt a 486 machine and when i boot up i get this message: CMOS checksum failure, Run setup utility, press F1 to continue.
It may sound simple but here is the problem. Keyboard will not respond, although it is a working unit i use on all my machines.Your help is appreciated.

 

[Mulga]

The checksum failure message on an old system like this usually indicates a dead battery, however this should not stop the keyboard working. I would suspect the motherboard (keyboard connector) is faulty. Not sure there is anything you can do about this with a 486, you can't use a USB keyboard.... maybe someone else has a suggestion All things are possible except skiing through a revolving door.

 

[gargouille]

Whatever method there is...use it to flush the BIOS...may have to take the battery out overnite...if there are no jumpers.
No other keyboard to try? (or tried that awready)
1 other thing...some of the older machines would skip to the emergency section of the BIOS to boot...in circumstances 'xactly like this...if you hold the insert key. Worth a try!

 

[edfair]

or possibly the other entry methods:
ctrl + alt + numeric pad +
C + A + numeric pad -
C + A + escape
[F2]
[F10]
or possible post back with the M/B info and you might luck into somebody with one still running.
And some M/Bs seem to be picky with connectors. You might want to try another keyboard. Or use a scriber point to close down the connectors. Ed Fair
unixstuff@juno.com
Any advice I give is my best judgement based on my interpretation of the facts you supply. Help increase my knowledge by providing some feedback, good or bad, on any advice I have given.

 

[ceh4702]

Checksum can be caused by bad or incompatable memory! Older computers often required the memory to be in a specific slot also. If you do not like my post feel free to point out your opinion or my errors.

 

[MrKovacic]

If you are creating this computer from older parts, the CMOS you are using may not be completly compat with the motherboard. If the keybord is a DIN or MiniDIN (PS2) and you get no numlock no matter what you do, you may have a faulty motherboard. This is assuming the keybord works in other systems. The keybord is a good indicator of the status of the motherbord. On most standard motherbords and CMOS, numlock is on by default. You may even have a faulty BIOS, but i doubt it. Check the condition of the motherboard, because a dead or missing bat will not return a checksum error, if anything, it will return a "check battery" error, or no error at all. You may be setting the CMOS setup every time you boot up. CMOS batterys can be bought at any RadioShack for under 5 bucks (usually).

 

[Mulga]

MrKovacic,
I have to differ with you on this, I have seen this error message many times on old systems caused by a dead CMOS battery. A lot of these old girls do not allow for auto detecting the IDE devices so when the battery goes no hard drive is detected which will give the checksum error on some boards. As for replacing the battery, it will most likely be one of the old, soldered in, barrel types rather than the batteries we are used to today. Sure these can be replaced but it requires some soldering expertise and a fair bit of care to avoid damaging the mobo. All things are possible except skiing through a revolving door.

 

[MrKovacic]

Mulga,
Good point. It has been a while since I was behint the board of an older machine. Now that you mention it, I do remember that. One good thing is that those old solder on types can be converted. It's no picnic, but I have seen it done. That may help a little.

 

[hylux82]

Thanks for all this info. Your suggestions are noted.With regards to Mr Kovacic's last reply,does he suggest installing an external batt,because if so I have already tried this option with no results.

 

[MrKovacic]

The the problem may not be the battery. If I remember correctly,CMOS takes 3 or 6VDC. Well, when you do find the answer, I would be interested on how it was fixed incase I run in to the same problem.

 

[edfair]

Most of the older soldered in types had 4 pin headers close by the battery with 2 center pins jumpered, which tied the battery to the chip. Replacement was to pull the jumper and plug the external battery on the 4 pin header strip. Ed Fair
unixstuff@juno.com
Any advice I give is my best judgement based on my interpretation of the facts you supply. Help increase my knowledge by providing some feedback, good or bad, on any advice I have given.

 

[pudda]

Have plenty of old 486's around and have seen this many times. The Cheapest fix I have run across is to purchase the older cordless phone batteries (amazingly the same voltage necessary) from the main shopping stores. Almost any one of them have a discontinued battery or two for sale. I then charge the battery using and old cordless phone and solder the wires to the proper connector for the computer and plug them in.
CMOS errors can be explained here:

http://www.computerhope.com/help/cmos.htm

 

[mainegeek]

Also, some of the older boards with the Dallas (black rectangle type) battery will generate a check sum error if you boot with the cmos jumper in the clear position.

 

[ceh4702]

I wouldn't even mess with a 486. Lets get realistic, it isnt worth spending money on something so outdated. There are probably a lot of P133 computers out there that are not even worth $50.00.

Old computers do make good Door Stops. If you do not like my post feel free to point out your opinion or my errors.

 

[ANFPS26]

ceh4702, there are a lot of 486 PCs still working fine. I've got one and I enjoy using it. Not everyone needs the "latest and the greatest"--plus there are lots of cheap parts lying around. Lots of people still like and use DOS and Win 3.1. It's whatever "floats your boat". "A little knowledge is a dangerous thing....."

 

[Newposter]

Very likely bad or incompatible memory, or not seated properly. This is the classic cause.

If you can get into the BIOS setup and set everything correctly, you don't need a working battery until you shut down/lose power. So don't waste time screwing with the battery. If you can't fix the problem with BIOS settings, it's the RAM.

I agree about tossing it and getting a low-end Pentium. Newposter
"Good judgment comes from experience. Experience comes from bad judgment."

 

[eurokev]

so general consensus is that it is RAM ?

I am rebuilding my system with an XP 1800 and an Abit kx7-333raid board. everything else is the same as with my old CPU and board.
I had the Checksum error message. If i reset enough times I get to use my keyboard for about two to three minutes before it locks completely. Have been into BIos settings and set the failsafe settings which get me into windows (twice in a zillion attempts, both times without keyboard or mouse working)
Also sometimes my machine locks up and just starts beeping.
I had trouble swapping the two sticks of ram from one board to the other. I don't want to offer easy solutions to you techies out there, but does this mean RAM is toast?
Any help would be appreciated, I've been on this problem for over a week, and I'm too stubborn to go and see a technician.
Thanks

 

[gargouille]

Best way to test RAM in the system (and remove any doubt) is to download any of the free RAM testing utilities...memtest comes to mind although I couldn't get it to run on a Win98 machine the other day. There are more here:

http://www.vml.co.uk/Frameset/Frameset master.htm

Then you can throw it away with relish!

 

[Silenced]

Hey guys, i have a win98 computer that is getting the cmos checksum error - defaults loaded error also. The system will read my ram and identify my ide's. I have no keyboard functions and the keyboard does work. I've left the battery out overnight and reinstalled it. No help with that one. I've also reconnected everything on the computer plus I've set everything on the board back to default which includes setting back to onboard video and removing my video card. I don't know what else I can do except to trash the board and buy a new one. Any advice will be greatly appreciated. The board is a DFI AK75-EC.

 

[oldbear]

Silenced...did you check the voltage of the battery you pulled out over night? did you reboot with the battery out? try a new battery...1.96 at wal mart if it's a regular 2032 (i think that's the number) ...keyboard not working sounds bad..have you tried a different working keyboard...is it plugged in all the way...sometimes you can go just a little ways into the socket with the keyboard connector and get stopped by the plastic surrounding the pins..and not make good contact thus rendering the keyboard useless untill you figure out it needs to be pushed in further...preferably without damaging the motherboard.