Hi, does the lamp work ? this a problem with panasonic sometimes. the lamp blows and kills part of the control panel pcb. Remove this and check for damage. if you find it do not repair the track, the problem is with one of the diodes on the board, just repalce the board, not the lamp waste of time.
kindest regards
B.E.S. Microwaves
01424 447799
microwave-repairs.co.uk
patrick
March 2009