T60 not switching to battery when power cord removed

[flakey1]

Hello, I own a T60 Type 2007 5tg, S/N L3 4r3g1 07/05. One day the laptop just powered off suddenly while in use. After that the laptop would not power on unless the mains cable is plugged in. The battery is not on the recall list, I've bought a new battery and it too does not work. I've observed a few things... OS is XP fully patched up. The IBM/Lenovo battery utility sees the battery at 83% charged and reporting that its working ok, the new battery is at 5%. Both batteries do not seem to be charging. When I power on the laptop, the battery light does 4 slow blinks followed by fast continuous blinking. I have replaced a broken keyboard, but that was over a month before this happened. Any ideas whats wrong? I don't think its the battery as I bought a new one.
has something blow or become loose that I can replace? I've searched this forum and all I can find are faulty battery issues, so any advice would be great. My 2 year old enjoys pulling cables so using the laptop is not much fun for me at the moment.

[richk]

It sounds like the power circuit on the motherboard has died. It is possible that it is a fuse, but even if it is, most repair places cannot replace the individual components.

[flakey1]

hi, were is the power circuit located on the motherboard? what are the tell tail signs of a blown fuse?

[richk]

There are lots of parts. They are located near the power jack and near the battery connection. The only sign of a blown fuse will be the fact that a meter will show an open circuit.