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From: jrs@zippy.unet.com (John Switzer Frame 3.0)
Subject: Re: CMOS Checksum error
Message-ID: <1993Apr21.202116.27892@unet.net.com>
Sender: news@unet.net.com
Nntp-Posting-Host: zippy
Organization: Network Equipment Technologies, Redwood City
References: <C5uAoq.5v@ulowell.ulowell.edu>
Date: Wed, 21 Apr 1993 20:21:16 GMT
Lines: 22

In article <C5uAoq.5v@ulowell.ulowell.edu> mcook@cs.ulowell.edu (Michael Cook) writes:
>Recently, I have been getting a CMOS Checksum error when I first turn on my
>computer.  It doesn't happen everytime I turn it on, nor can I predict when it
>is going to happen.  I have an AMI BIOS and all of the setting are lost, for
>example the drive types and the password options.  However, the date and time
>remain correct.  If anyone knows what can be causing this, please let me know.

Most likely reason is that your backup battery is failing - this battery 
maintains the contents of the CMOS memory when AC power is turned off, and
if the battery is flakey then the contents of the CMOS will be lost and 
the checksum will be wrong (along with most other of the CMOS data). Try 
replacing the battery.

If, however, your PC doesn't use a battery but a large capacitor to power
the CMOS, you should check to see if you can replace the capacitor with a 
more normal lithium battery. If this isn't possible, make sure you leave
your PC on for a half hour or hour each day; this will keep the capacitor 
charged. I'd opt for the battery change, though.

It's also possible, but unlikely that a rogue problem or even a virus is 
corrupting the CMOS. If your battery seems okay, get a virus scanner and
check out your system.
