Wont heat ,,,,,,,,

If your oven has a stirring antenna in the waveguide, make sure the antenna is rotating. An easy way to check for this is to put in a glass pie pan with just enough water in it to cover the bottom. If you see one or two hot spots where the water quickly boils, the antenna is not turning.

If you have a high voltage probe, measure the voltage at the magnetron end of the diode. (DO NOT try a spark test!) If you get none, then check the door switch in the transformer circuit and check the magnetron power relay on the controller. If those are good, check the capacitor.
If you get high voltage, and you have already verified that the stirring antenna is working, then the magnetron is bad. A common failure in Sanyo/GE microwave ovens is a weakening of the magnet in the magnetron. If the magnet is not strong enough to hold a standard-length #2 Phillips screwdriver shaft to the bottom of the magnetron, it's faded out. (It's a design flaw - the magnetic material lacks has insufficient remanence, and is placed too close to the transformer so the alternating magnetic field from the transformer gradually erases the magnet.)