Member Panel

My C400 P3, 1.2 Ghz, 1GB RAM, Windows XP, suddenly turns off when the battery is inside the battery bay and the AC adaptor is plugged. Runs fine on battery alone or on AC plug alone. I tried a new battery and it does the same. I tried a different AC adaptor and it does the same too, dies within a few minutes. The Bios Battery monitor shows that the battery is charging, but the laptop turns off when a 20% of battery charge is reached. Has anyone seen this problem on a DELL C400 (or any laptop for that metter)
Thanks for your comments

Laptop motherboards have built in power-management circuitry...
I am afraid yours has perhaps failed... it would seem to explain all your symptoms. It is probably set up to default to undercharge the battery--overcharging can be quite dangerous.
Causes fires.
Unfortunately the solution is a new mobo ( or a new laptop)
Sorry.