Forum Home
Press F1
 
Thread ID: 45067 2004-05-08 03:57:00 CMOS Checksum Incorrect Woody (710) Press F1
Post ID Timestamp Content User
235187 2004-05-08 03:57:00 I frequently get "CMOS Checksum incorrect. Defaults Loaded Press F1 to continue" error on bootup. Normal after pressing F1
Recently in addition I found that the date/time had reset to 1/1/2003 00.00pm
Machine is P4, 256Mb RAM, PC Co ( now belly-up)
Any suggestions please.
Rgds
Woody (710)
235188 2004-05-08 04:06:00 Sounds like your battery might be dead/dying. The BIOS requires the battery to hold your settings - if it dies, the settings are reset.

You can replace PC batteries fairly easily.

Mike.
Mike (15)
235189 2004-05-08 04:06:00 There isa battery which keeps a clock running when the computer is off, and also maintains the CMOS memory which holds the BIOS settings.

You need a new battery. It is most likely a lithium button cell (probably a "2032"). It is a 20 mm diameter disk looking like a coin. Be careful removing the dead one --- it's easier to break the clip than it is to fix it. ;-). The Warehouse or an electronics shop will have the replacement.
Graham L (2)
235190 2004-05-08 04:18:00 The model number is usually printed on the battery/cell itself. agent_24 (4330)
235191 2004-05-08 04:40:00 Thanks fellows
I was sort of thinking along those lines but the PC is only oneyear old and I figured that the battery would have lasted longer but I'll certainly check on that.
Would a dying battery give the checksum error as well?
rgds
Woody (710)
235192 2004-05-08 04:44:00 Further to my prev post - will the rest of the CMOS settings eg HD, partitions etc hold whiile replacing the battery? Woody (710)
235193 2004-05-08 04:44:00 The checksum error and the clock stopping make me certain that the battery is dead. They should last longer. Some don't. ;-) Graham L (2)
235194 2004-05-08 04:49:00 The partition tables aren't in the CMOS. They live on the disk. The autodetect and default settings seem to be OK --- they are what you are getting when you "press F1". The settings are being lost each time the computer is off for a few hours.

When you replace the battery, you will need to use the BIOS setup, (select the default settings and set date and time) and "Save and Exit" to get rid of the error message.
Graham L (2)
235195 2004-05-08 04:50:00 Thanks Graham. Will do
Rgds
Woody (710)
235196 2004-05-08 04:54:00 yea, most motherboards come with a battery, and i suppose they use half-price 10 year old ones agent_24 (4330)
1