Toshiba satellite A210 11-P crashes when i...

Question

Despite the battery showing 100 per cent fully charged if i switch the power cable off from the mains supply and remove it to use the laptop fully portable it crashes and keeps allternating from black screen to blue screen.If i press the Enter key at the black screen command option Start Windows Normally it tries to boot but keeps failing and doing the same thing.When i reconnect the mains power it boots up and works o.k.The machine can only be used permanently plugged in the to the mains.I phoned Toshiba technical support and the bios was updated but it did not solve the problem.This machine is just over 1 year old and out of warranty.All help will be much appreciated Thanks.