Thinkpads Forum

I have an old IBM 390X with Windows XP Pro. I think the CMOS battery has run out because it gives me a "Real Time Clock" error in the bios, but I push F1 to continue to XP. The fan also runs at max when in the bios but quits when XP loads. When it gets hot again the fan will go to full.

I can't find the CMOS battery. I took out the keyboard but there was no CMOS coin battery in sight. I also opened the RAM covers but found no battery. I heard that a dead CMOS battery can lead to fan on/off malfunctions. It would be a shame if this 10 year old computer fried because of a dead 3V battery.

On the bottom of the machine there is a little cover, similar to the ram cover.
You should find the modem card and the cmos battery below that cover.
The Hardware Maintenance Manual says that you have to take the modem card out to get to the cmos battery.

When I turn the machine over there is a cover on the left side near the modem port. However, the place where the screw is, is covered. How do I get that cover off?

The little round black screw cover may still be there. It is held in place with a little glue, but the glue is not that strong.
The screw cover can easily be taken of. A small sharp knife will be fine to get hold of it.
Also you should be able to put the screw cover back on using the existing glue.

Thanks, it word perfectly.