Battery doesn't charge ("Not Charging" followed by "No Battery")

Hi Everyone.

I've got a question about a 1.5 GHz PowerBook G4 (A1095) that won't charge its battery.

Immediately after the computer is booted, the battery is recognized, but is listed as "Not Charging". A few minutes later, it disappears, and the status changes to "No Battery".

At first, I thought that the (rather old) battery had finally died. However, when we swapped in a new battery, it had exactly the same problem as the original battery, indicating that something is probably wrong with the computer itself. I've tried resetting the PMU, as well as booting off of a different disk, so it's unlikely to be a software issue.

I could see this being either a logic board problem or a DC board problem, and I was wondering if anyone had a guess as to which one it might be (or if the problem might be something else). A quick visual inspection inside the machine didn't yield any obvious information (e.g., visibly failed components).

If it helps to narrow it down at all, both the logic board and the DC board have small preexisting problems. The logic board has the all-too-common dead memory slot, and the power socket is slightly loose (i.e., the AC adapter sometimes requires a bit of fiddling to yield an illuminated LED, thus providing an excellent illustration as to why MagSafe was a good idea).

Thanks very much.

Cheers,

Jonathan