you must two options: a) call some tech professional b) or do it yourself.in b) case you must have some skill, will you do that? see the diagrams attached.God bless you
some switches are normally closed "short position" press switch "open" it will be labeled NC on the one side, "stands for normally closed" and others will be NO "stands for normally open" press switch "short" if there is no change in readings when you press switch it is defective.
Take warm soapy water and clean until spotless, if no change! check microwave hood for bare metal, if okay! the magnetron is breaking down and will eventually fail.
Take warm soapy water and clean until spotless, food partical build up will cause arcing, if no change! the microwave hood is a another trouble spot, if any bare metal is showing it will arc and need to be replaced, if everything checks out the magnetron is bad and will eventually fail.
The remedy is to change it to a good one as it can cause more damage to your microwave... the cost of one high voltage fransformer is about 90.00 and the cost of repair can be from 100.00 to 200.00...its best you buy a new microwave as the damage might lead from one problem to the next..good luck.
The problem is one of three things, the magnetron "common issue" or the high voltage capacitor and diode can be a factor, the above mentioned work together to heat food. Depending on the nature of the repair, parts and labor can run as high as a new microwave oven.
