Toshiba notebook I tried to plug in computer the socket sparked, now I am unable to turn the comp;uter on.

This may be because:
1) The adapter has fried.
2) The battery has short circuit.
3) Or the motherboard.

If this is due to motherboard, you may be in serious problem.
To check the battery and adapter test them individually on a separate system.
In my knowledge it is the adapter which has fried up and I think you are running your system on DC most of the time.

Either a bad AC adapter or a short in the motherboard.

Try another adapter. If that doesnt do it the machine will have to be taken apart by a good tech who can trace power circuits on the motherboard.