Where to get clear diagram of magnetron circuitry with capacitor and diode circuits shown ?

If the proper voltage is coming into your control board and you are not getting voltage at the MW relay, then you need to replace the control board. If voltage is interupted by a thermostat or switch from your testing to the control board, then replace that part.
Now, testing from the MW relay on to your transformer, high voltage capacitor, magnetron, and diode.Do not do any voltage reading from the secondary side of the transformer on, this can be a deadly microwave oven repair if you do not follow directions. This can result in electrocution and the "blowing-up" of your voltmeter, only do OHM testing with the power off and the capacitor discharged. Someplace in this circuit, usually before the transformer, you will have another thermostat to test. It is usually mounted on the magnetron. Do a quick OHM test to see if it is open or closed.
Now to test either the transformer, high voltage capicitor, magnetron, and diode, you must test each part separately. A good rule of thumb, if your capacitor is bad, change the diode also. Another note, if you are working on an OTR model and you have determined to be one of these "heating" circuit parts, you can not test these parts until you take the unit down. If you don't have the parts with you and you have to order them, order the magnetron, capacitor and diode and you will have a 90% chance of solving the problem. If it is an older microwave, order the thermostat also, most times you can return un-used, un-opened parts. Check with your parts supplier. This way you only have to take the unit down once.
To test these parts, scroll down this page and you will see a chart with component tests. Follow the instructions to find which part(s) are defective in your microwave oven repair.
use the VOM. God bless you

If the proper voltage is coming into your control board and you are not getting voltage at the MW relay, then you need to replace the control board. If voltage is interupted by a thermostat or switch from your testing to the control board, then replace that part.
Now, testing from the MW relay on to your transformer, high voltage capacitor, magnetron, and diode.Do not do any voltage reading from the secondary side of the transformer on, this can be a deadly microwave oven repair if you do not follow directions. This can result in electrocution and the "blowing-up" of your voltmeter, only do OHM testing with the power off and the capacitor discharged. Someplace in this circuit, usually before the transformer, you will have another thermostat to test. It is usually mounted on the magnetron. Do a quick OHM test to see if it is open or closed.
Now to test either the transformer, high voltage capicitor, magnetron, and diode, you must test each part separately. A good rule of thumb, if your capacitor is bad, change the diode also. Another note, if you are working on an OTR model and you have determined to be one of these "heating" circuit parts, you can not test these parts until you take the unit down. If you don't have the parts with you and you have to order them, order the magnetron, capacitor and diode and you will have a 90% chance of solving the problem. If it is an older microwave, order the thermostat also, most times you can return un-used, un-opened parts. Check with your parts supplier. This way you only have to take the unit down once.
To test these parts, scroll down this page and you will see a chart with component tests. Follow the instructions to find which part(s) are defective in your microwave oven repair.

If the proper voltage is coming into your control board and you are not getting voltage at the MW relay, then you need to replace the control board. If voltage is interupted by a thermostat or switch from your testing to the control board, then replace that part.
Now, testing from the MW relay on to your transformer, high voltage capacitor, magnetron, and diode.Do not do any voltage reading from the secondary side of the transformer on, this can be a deadly microwave oven repair if you do not follow directions. This can result in electrocution and the "blowing-up" of your voltmeter, only do OHM testing with the power off and the capacitor discharged. Someplace in this circuit, usually before the transformer, you will have another thermostat to test. It is usually mounted on the magnetron. Do a quick OHM test to see if it is open or closed.
Now to test either the transformer, high voltage capicitor, magnetron, and diode, you must test each part separately. A good rule of thumb, if your capacitor is bad, change the diode also. Another note, if you are working on an OTR model and you have determined to be one of these "heating" circuit parts, you can not test these parts until you take the unit down. If you don't have the parts with you and you have to order them, order the magnetron, capacitor and diode and you will have a 90% chance of solving the problem. If it is an older microwave, order the thermostat also, most times you can return un-used, un-opened parts. Check with your parts supplier. This way you only have to take the unit down once.
To test these parts, scroll down this page and you will see a chart with component tests. Follow the instructions to find which part(s) are defective in your microwave oven repair.