Electric Seat Problem

[Foxymark]

Just bought an A4 Cab, the drivers seat has stuck at the top of its travel and wont move on the electrics, i can hear the motor trying to come in but no joy, i cant locate the motor under the seat either.

Is the adjustment method through a screw driven by the motor and if so are there any known problems with maybe overtravel on the screw?

any help greatfully taken, its driving me nuts