Ok, I have come across a problem with one of my laptops, an old toshiba tecra 8200, which seems very unusual. I realise this is quite an old laptop, but I would like to fix it if at all possible.

the laptop was running all day, then suddenly in the evening it shut off, no "windows is shutting down" etc, it just shut off as if I had held down the power button. now, when turned back on the battery monitor said that both batteries (it has a second battery installed in the bay where a cd drive usually sits) were totally empty. now, i thought this was odd because at no point did any of the power saving measures such as dimming the screen activate as though it had come un-plugged. anyway, i left it overnight charging, and checked in the morning when i turned it on and both of the batteries were fully charged.

now, later that day, despite not being un plugged one battery had completely drained and the other was at 16%, about 10 minutes later it shut off again. In addition all day the "charging" light had been lit. I turned it on again and windows didn't even load before it shut off again.

so, assuming this was just a problem with the batteries I removed both of them, however when I tested the laptop in this way it shut off again just after windows loaded.

I put the batteries back in, and left it to charge the batteries overnight (the laptop was off) however this morning i found that only one was charged to 20%

I have tried cleaning it, thinking it could be an overheating problem in the internal power supply, although I am out of airduster at the moment so i will try doing a proper job later today. I have also tried a different power supply, so that rules out the power brick being busted.

I am guessing that it is something on the motherboard busted, either the internal DC-DC power supply or the power jack itself. either way the motherboard will need replacing if it is either of these things. however, i was wondering if anyone else had experienced a similar problem with a laptop. and/or had any suggestions on a possible alternative solution?

thanks in advance!