755C won't charge battery

[pyl85]

Hi,
I've got a Thinkpad 755C 9545-L0G that will not charge a battery. I've got 4 different batteries for it. 2 are probably bad, but 2 I bought off of ebay about a year ago saying they would take a charge.

When the computer is running plugged in, the Fuel program simply lists all the batteries at 0%. Clicking on discharge does nothing.

When running, the battery light is always green and the light next to it is green also. When switched off while still plugged in, no lights at all.

I called IBM tech support a while back and they said that if either the standby battery or the CMOS battery was dead, it wouldn't charge a battery. I have since replaced both, the backup battery with the appropriate model and I just stuck a CR2032 in for the CMOS (same voltage as the the VL2020, higher amp rating).

Anyone seem anything like this before? What do those little switches on the battery do?

Thanks,
Greg

[POULSBOLIBRARYGUY]

Wow-I just joined this board, and now it's nice to know someone else has the same problem. Since we have the same computer, could it be something with the 755Cs?

[JBUK]

As far as I recall this is usually caused by a failed dc-dc board.
This is easy enough to change if you can get hold of one.