Battery Charging Problem

[Rob]

Hey, I've got a problem with my old ThinkPad 770ED. One day, the battery stopped working in the main battery bay. When it's plugged in the gauge works, but it won't charge or discharge from that bay.

It works in the Ultrabay though. Does this sound like a bad connection issue, or could something have gone wrong?

Rob

PS - What does the DC/DC card on a 770 do?