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.

 

[KimberTech]

For my $.02, I have seen this a few times on 486's, and a lot of my clients use these still.
They make a great packing slip computer etc.

The last one I did has the DALLAS chip that was mentioned in one of the above threads. The fix was to replace the chip. We replaced the system. The chip wasnt holding the CMOS settings .... CMOS was reset each time it booted loading failsafe/default settings.

One of the other ones was a bad keyboard connector. If the bios was set to stop on all errors, it would give you the checksum error...tell you to enter setup. Of course you can't because you have no KB. If you can get in set to stop on no errors if possible..depends on Bios version. Kimber

The more I learn,I realize how much more there is to know!

 

[Silenced]

Oldbear,
Thx for the info. I checked the keyboard and its all the way in, also i thought about checking the keyboard to see if any keys were stuck or if it wasnt functioning anymore by using it on my laptop. I found that it stills works and that no keys are sticking. I think ill run out to wal*mart and purchase a new battery. If that doesnt work i really dont know what i can do next. Im looking at purchasing an Asus A7N8X Deluxe mobo. any new advice will be appreciated

 

[oldbear]

Those old Dallas timing chips normally have just a plastic cover with DALLAS printed on it. Once you pop the plastic cover off you will find a timing chip with pins and a little battery soldered onto two pins. I have replaced that battery and solved the error problem mentioned...new battery holds the bios settings...be very careful of breaking the pins...better to desolder or cut the battery off (very carefully) and not bend the pins at all

As for old 486's..seen lots of them still in use even today ...very low cost internet access...still does what many people need to do.

 

[KimberTech]

oldbear-
I have some old Dallas chips around here...
going to dissect one to see what you are saying.
Thanks for the tip Kimber

The more I learn,I realize how much more there is to know!

 

[mainegeek]

There should be a 4 pin header for a replacement
battery as EdFair mentioned. Probably 3.6 volts which you can find at radio shack. You may need to swap the end with a connector from a cdrom audio cable to get it to fit. Even some 386's allowed for this.

 

[Silenced]

Well guys ive decided to trash my mobo. Ive tried everything from battery to brand new hardware. Theres just no hope for it anymore. Now Im looking at an Abit NF7-S, AMD 2400+ XP, and 512 DDR just to start things off. If this system works well ill report about its pros and cons. thx for all the help.