No power to microwave - Microwave Ovens

F7 means power to magnetron is interrupted.

I don't recommend that someone without experience and an understanding of the safety procedures undertake troubleshooting this.
You can find manuals and helpful exploded view diagrams for your model here and my favorite parts supplier is here. There is a technical sheet hidden behind the controls that has helpful technical and troubleshooting information. It will say something like this:

F7 Power to magnetron interrupted

1. Unplug microwave oven or disconnect power.
2. After 40 seconds, check to see whether this solves the problem.
3. Unplug microwave oven or disconnect power.
4. Check cooling fan operation
5. Check the magnetron.
6. Check P65 connection on the relay control board.
7. Check the P56/P66 connection between relay board and relay control board.
8. Check wiring to the 1200W inverter and control system. See "Checking Inverters."
9. Check operation of all interlock switches.
10. Replace all parts and panels before operating.
11. Plug in microwave oven or reconnect power.
12. Check voltage at 4903-1 on relay board. If it is 120, unplug microwave oven or disconnect power.
13. Replace inverter.
14. Replace all parts and panels before operating.
15. Plug in microwave oven or reconnect power.
16. If problem persists, unplug microwave oven or disconnect power.
17. Replace relay control board.
18. Replace all parts and panels before operating.
19. Plug in microwave oven or reconnect power.
20. If problem persists, unplug microwave oven or disconnect power.
21. Check for reversed plug connection on controls or loose wiring.
22. Replace all parts and panels before operating.
23. Plug in microwave oven or reconnect power.

William E. Miller, AS-EET
http://www.MicrowaveControl.com
Microwave Oven Control Panel Repair Nationwide
"Recycling by repairing since 1982"

Disconnect the microwave from the power source while the power is still out. If the microwave is a built-in, turn off the circuit breaker. Otherwise, unplug the microwave from the wall outlet. This prevents a power surge from damaging the magnetron tube when the power is restored.Turn on the circuit breaker or plug the microwave into the outlet only when you are sure that the power is permanently restored. If there are still storms in the area, the power may be disrupted again. Reset the clock on the microwave. Microwaves vary slightly on how to set the clock, but usually there is a clock button you press. Use the number pad to input the correct time and press the clock button again to set it. Test the microwave by heating some water to ensure that it is still in good operating condition.

The magnetron has probably shorted, and in rare cases the power transformer will fail, "but unlikely"

Hello

and/or circuit breakers, particularly in the case of recent power failure, and reset if necessary.


Unplug the microwave, wait 30 seconds and plug back in to the power supply to reset the microcomputer.


Open and close the microwave door firmly and press "Stop/Reset." Select a new cook time and press "Start."


Ensure a proper cooking temperature and/or time is chosen, as low cooking temperatures or short cooking times may prevent the microwave from heating food appropriately. Press "Power Level" to ensure the microwave is cooking at 100 percent power.


Contact an authorized service technician if the problem is still unresolved.

F3H Humidity sensor failure 1. Unplug microwave oven or disconnect power.
2. Connect a new sensor to the board (at P5).
3. Plug in microwave oven or reconnect power.
4. If no failure code appears when starting sensor function:

Unplug microwave oven or disconnect power.

Replace old sensor.
5. If failure code appears when starting sensor function:

Unplug microwave oven or disconnect power.

Replace power supply board.
6. Plug in microwave oven or reconnect power.

The microwave oven should be at a temperature above 50°F (10°C) ... microwave oven can be manually set to defrost. To defrost. manually, use 30% cook power. ...

www.whirlpool.com/assets/pdfs/product/ZUSECARE/8205987.pdf

F7 is q Power to magnetron
interrupted

1. Unplug microwave oven or disconnect power.
2. After 40 seconds, check to see whether this solves the problem.
3. Unplug microwave oven or disconnect power.
4. Check cooling fan operation
5. Check resistance of the magnetron thermostat.
6. Check the magnetron.
7. Check P2, P4 and P27 connections.
8. Check wiring to the 1100W inverters and control system. See
“Checking Inverters.”
9. Check operation of all interlock switches.
10. Replace inverter, if defective.
11. Replace all parts and panels before operating.
12. Plug in microwave oven or reconnect power.
13. If problem persists, unplug microwave oven or disconnect power.
14. Replace electronic control.
15. Replace all parts and panels before operating.
16. Plug in microwave oven or reconnect power.
17. If problem persists, unplug microwave oven or disconnect power.
18. Check for reversed plug connection on controls or loose wiring.
19. Replace all parts and panels before operating.
20. Plug in microwave oven or reconnect power.

Try change the fuse.

check the control unit and highvoltagae areaand megnetron , related circuit..