Microwave shows code F7. The repairman was here weeks ago and said it was either the control board or the inverter. He ordered both, came back today, tried replacing both and still doesn't work. He said tech support isn't available to him on Saturday. His best guess is the replacement inverter is no good either. That would be a huge amount of bad luck. The microwave is only 16 months old. The model is GH5184XPB-7

F7 Error Code On Microwave Ovens With Inverter Board

An F7 error code could be an inverter board failure. Anything else that prevents microwave energy may also cause an F7 error, and must be checked. The technician should perform the following procedure to test for an F7 error code:

1. Check the magnetron.
2. Check the magnetron TCO (it should be closed).
3. Check the 3 interlock switches.
4. Check the harness wiring.
5. Check the electronic controls.
6. Check the inverter board.

For more free help, feel free to contact me via my site with your detailed symptoms and full model number and FCC ID number as shown on the tag in or on the oven.

There should be a "mini-manual" (tech sheet) hidden inside the unit behind the control panel or hidden on the left side behind the grille, which is very helpful when troubleshooting, testing, and locating components. It should cover an F7 error code.

A video is available here showing how to remove a typical over the range control panel assembly in under 5 minutes.

This may help:

F7 Error Code On Microwave Ovens With Inverter Board
MODELS: GH9177XL, GH9185XL, MH9180XL, MH7155XMS, & KHHS178L for example

An F7 error code could be an inverter board failure. Anything else that prevents microwave energy may also cause an F7 error, and must be checked. The technician should perform the following procedure to test for an F7 error code:

1. Check the magnetron.
2. Check the magnetron TCO (it should be closed).
3. Check the 3 interlock switches.
4. Check the harness wiring.
5. Check the electronic controls.
6. Check the inverter board.

You can find links to helpful exploded view diagrams and part ordering help here.

I recommend that you bookmark that link to your favorites.

I am having the same problem. According to the owner's repair guide error Code F7 indicates that power to the magnetron was interrupted. You will want to make the following checks: 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 resistance of the magnetron thermostat. 5. Check the magnetron. 6. Check wiring to the 1100W inverter and control system. See "Checking Inverters." 7. Plug in microwave oven or reconnect power. 8. Check operation of all interlock switches. Check door, hinge and cavity front alignment. Adjust as needed. 9. Unplug microwave oven or disconnect power. 10. If switches operate correctly, replace 1100W inverter. 11. If problem persists, replace electronic control. 12. Plug in microwave oven or reconnect power.

While this is helpful, it is still out of my confort zone as I pulled the control panel and discovered a virtual zoo of connectors. Obviously ponly a trained repairman knows which ones need to be checked. I will probably have to resort to calling one and shelling out the dough.

The controller is not getting the high voltage switched-mode power supply feedback signal.

Sometimes this is due to a defect on the HVSMPS (inverter) or a bad connection from the HVSMPS to the controller.

Due to the voltages involved, I do not recommend that an inexperienced person attempt to troubleshoot an inverter.

In the event that you or someone you know wants to look into it, see these safety warnings first.

There should be a "mini-manual" (tech sheet) hidden inside the unit behind the control panel or hidden on the left side behind the grille, which is very helpful when troubleshooting, testing, and locating components.

It tells you 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.

I'd suspect 6 through 8 first.

You can find helpful exploded view diagrams and order parts by entering your full model number from the tag on the oven here.

We're happy to help you with free advice and we'd appreciate your thoughtful rating of our answer.

According to the technical sheet found hidden inside the unit behind the controller and online here:

F7 Power to magnetron interrupted
1. Unplug microwave oven or disconnect power.
2. After 40 seconds, check to see whether this solves the problem. (Possible reason: Over temperature protection for the magnetron opened.)
3. Check resistance of the magnetron thermostat. It should be close to 0 ohms.
4. Check the magnetron.
5. Check wiring to the 1100W inverter and control system.
6. Check operation of all interlock switches.
7. If switches operate correctly:
- Replace 1100W inverter.
- If problem persists, replace power supply board.
8. Plug in microwave oven or reconnect power.

You can find helpful exploded view diagrams and order parts by entering your full model number from the tag on the oven here.

We're happy to help you with free advice and we'd appreciate your thoughtful rating of our answer.

An F7 error code could be an inverter board failure. Anything else that prevents microwave energy may also cause an F7 error, and must be checked. The technician should perform the following procedure to test for an F7 error code:

1. Check the magnetron.
2. Check the magnetron TCO (it should be closed).
3. Check the 3 interlock switches.
4. Check the harness wiring.
5. Check the electronic controls.
6. Check the inverter board.

There should be a "mini-manual" (tech sheet) hidden inside the unit behind the control panel or hidden on the left side behind the grille, which is very helpful when troubleshooting, testing, and locating components.

At our Web site, we have a video available showing how to remove a typical over the range control panel assembly in under 5 minutes.

If you don't find yours, or if you want to look at it without disassembling the oven, you can download it here.
You can find links to helpful exploded view diagrams and part ordering help here.

I recommend that you bookmark that link to your favorites. We're happy to help you with free advice and we'd appreciate your thoughtful rating of our answer.

For model KHHS179LWH2, from the tech sheet located behind the controls or found online here:

F7 Power to magnetron interrupted

1. Unplug microwave oven or disconnect power.
2. After 40 seconds, check to see whether this solves the problem. (Possible
reason: Over temperature protection for the magnetron opened.)
3. See safety info here, then check resistance of the magnetron thermostat. It should be close to 0 ohms.
4. Check the magnetron.
5. Check wiring to the 1100W inverter and control system.
6. Check operation of all interlock switches.
7. If switches operate correctly:
- Replace 1100W inverter.
- If problem persists, replace power supply board.
8. Plug in microwave oven or reconnect power.

At our Web site, we have a video available showing how to remove a typical over the range control panel assembly in under 5 minutes.

You can find links to helpful exploded view diagrams and part ordering help here.

We're happy to help you with free advice and we'd appreciate your thoughtful rating of our answer.

Assuming yours is a model KHMS2050SSS0, here is what the technical sheet says about the F7 error code:

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.

(This troubleshooting guide presumes one does not know how to test electronic components. That's why they say to replace and part and check it again.)

You can find helpful exploded view diagrams and order parts by entering your full model number from the tag on the oven here.

If yours is a different model number, please reply back.

There should also be a "mini-manual" (tech sheet) hidden inside the unit behind the control panel or hidden on the left side behind the grille, which is very helpful when troubleshooting, testing, and locating components.

It says:

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.

If for some reason your tech sheet is not there, you can download it here.

We regularly repair control units for customers nationwide by mail for $39.95 postpaid in about a week with a one-year guarantee.

Feel free to contact me directly (and please remind me of your full model number) for more information & help.

We're happy to help you with free advice and we'd appreciate your thoughtful rating of our answer.

William E. Miller
[email protected]
http://www.microwavedisplay.com

The 665 the model number prefix means it's made by Whirlpool. F7 means it has a problem with the control board or keypad.

The first thing to try is a "hard reset". Unplug it from the power line for a minute, plug it back in, set the clock, then try again.

If it still has a problem, we repair these for customers nationwide with our guaranteed $39.95 service. If a new keypad were needed, that would add about $60 to the repair cost.

Please feel free to contact me directly if you need more help.

We're happy to help and we appreciate your thoughtful rating of our answer.

William E. Miller, AS-EET
[email protected]
http://www.microwavedisplay.com