Hi, F12 if memory serves is lower magnerton circuit failure, note not necessarily the magnetron, possibly the capacitor or a gritty joint to the mag from the lv side. Danger exists here for the untutored. these machines can and kill, yes even when unplugged. get a pro. probable cost circa £100 including repair, parts, and safety test.
kindest regards
patrick
microwave-repairs.co.uk
patrick, March 2009
