A31: Date/Time error with any CMOS battery

[DoctorLondom]

I have an A31 that I am working on, type # 2652-M3U, and it displays the "Incorrect Date/TIme" error and loses BIOS settings every time the main battery is pulled. Obviously, this is a bad CMOS battery, but I have replaced it with brand-new batteries as well as tested-OK batteries from other A-series machines with no luck.

I am starting to think the motherboard is bad, since the previous owner had put T23 lid antennae across the insides to give it wireless capability (which did not work as the bare metal antennae were grounded by the chassis). However, that's pretty strange for only the CMOS battery to have been affected as the rest of the machine is fine.

Does anyone have any input on this issue, or know of a possible fix? Is there a fuse for the CMOS battery that could be easily replaced?

Please let me know.

[RealBlackStuff]

Check that the battery connector on the motherboard has not come loose.
Try using a multimeter with needles as test-pins, and see if you can find a current on the mobo around that CMOS connector, to verify.

[DoctorLondom]

I took out the motherboard, and found some battery acid-like corrosion around the transistors near the battery plug. I washed it off with some contact cleaner but the problem persists. I don't feel comfortable desoldering any components or replacing them as the computer still works fine. I will be selling it in the Marketplace here.