I did the same as AKC for his TV630 - it was the Thermal fuse (184 degrees) on black wires of heater element at back of machine.
Remove rear silver cover.
Disconnect all 4 wires in side machine - wires have thermal covering. Replacfement fuse from maplin - code RA19V - cost 59 pence. Crimp (best ot to solder) new one in.
J7
October 2005