Is there a brightness control anywhere? Or do we need to replace the display?

⟐ Answer accepted febbraio 06, 2026 at 6:04 GMT-7

⟐ Commented febbraio 03, 2026 at 13:36 GMT-7

I have a Whirlpool 1.7 wmh73l20as, It has power and doesnt show any errors on the touch panel. Every time I press the start button, the microwave switches on momentarily (less than a second) and just shuts down again and again. Any help in diagnosing the issue and potential solution will be much appreciated. Thanks in advance.

⟐ Commented febbraio 03, 2026 at 10:17 GMT-7

Any suggestions?

⟐ Commented febbraio 03, 2026 at 6:43 GMT-7

⟐ Answer edited febbraio 02, 2026 at 18:19 GMT-7

⟐ Commented febbraio 01, 2026 at 13:33 GMT-7

⟐ Answer accepted gennaio 22, 2026 at 8:44 GMT-7

I've been using this microwave for around a year without any issues. This started happening in the past few days. The breaker is a 20A breaker, which I think is shared between the fridge, stove, and microwave. Again, this worked for about a year without issues. The microwave alone pulls 12A.

I used my multimeter's continuity test, and confirmed that both thermostats and all 3 door switches are working. The only thing that didn't pass the continuity test is the lamp unit (Light Bulb). The lamp unit has 66 ohms of resistance. However, the light turns on every time I open the door. The internal fuse also has continuity, here's a picture of it.

While keeping the fridge and stove operating, I also plugged a kettle into the same outlet, which didn't trip the breaker. The kettle draws around 9A.

I tried finding parts diagrams or wiring schematics, but can't find any. If anyone got any insight on this, that'd be greatly appreciated!

⟐ Answer edited gennaio 13, 2026 at 21:42 GMT-7

and how to fix it?

⟐ Edited gennaio 21, 2026 at 17:56 GMT-7

⟐ Answered gennaio 05, 2026 at 20:15 GMT-7

⟐ Commented gennaio 03, 2026 at 0:34 GMT-7

I have a russell hobbs microwave which I can't stop. It runs without heating constantly. The light is on, the fan is on and it's turning but not heating. I can still use it but i have to turn it off at the wall tostop it running. Any ideas?

⟐ Commented dicembre 31, 2025 at 7:54 GMT-7

(I have read the other fan-related postings but they do not seem to apply)

I had a thermal fuse blow and the microwave would not start at all, so I replaced it. Specifically, the thermal fuse behind the control panel facing toward the back of the microwave (fuse KSD-40LC 70). The thermal fuse nearby facing downward had no continuity problem so I left it in place.

After replacing the thermal fuse, when I plug the microwave in, the vent fan immediately starts running on Medium speed and the control panel is all lit up with weird symbols. I press the Cancel button and the control panel clears, but the vent fan continues to run. This is the case with the door open or closed - doesn't matter. If I try to turn off the fan with the Vent Fan button, it cycles from Medium to Boost to High and back to Medium, but doesn't go to Low or Off.

Note that the microwave heats just fine - the vent fan is simply always on.

Here is what I have checked so far:

I re-checked the other thermal fuse behind the control panel and it still has continuity.

I checked all the door switches and they all seem fine - either continuity when the door is shut and not when the door is open, or continuity when the door is open and not when shut - i.e., they seem to be doing exactly what they should be using the actual door for testing.

Here are some ideas I have based on research:

Is there a thermostat (or other sensor) somewhere other than behind the control panel - possibly related to an "auto cooling" feature - that instructs the fan to run if it thinks the microwave is too hot? This is an over-the-range model and I read that some models have this feature in case the stove below made the microwave too hot and this feature supersedes the vent controls until it not longer thinks it is too hot. Not sure if this model has this feature.

I saw a case for another microwave where the "vent damper" component (controlling flap leading to exhaust outlet) had something wrong with it and that caused the fan to continue running. I do not know if this model has such a mechanism.

My initial fixes and testing did not require me to unmount the microwave. I am willing to do so but wanted some sense of direction rather than just starting to take it apart to see what I find.

⟐ Commented dicembre 29, 2025 at 20:51 GMT-7

⟐ Edited dicembre 27, 2025 at 7:40 GMT-7

⟐ Commented dicembre 20, 2025 at 20:58 GMT-7

⟐ Commented dicembre 19, 2025 at 23:26 GMT-7

⟐ Commented dicembre 15, 2025 at 1:33 GMT-7

Came to me with a blown fuse. Disconnected power, checked HV capacitor was discharged, and began troubleshooting.

- Tested the 3 door switches and power relay connected to PCB. Switches tested correctly with door open and closed, multiple times.

- Checked door latch alignment. Nothing loose or out of alignment.

- Checked for signs of loose connections, wiring issues, burns or signs of overheating. Everything looks good.

- Checked all other major components for possible issues, shorts. Nothing found.

Replaced fuse, button-up cabinet, connect to power, open and close door multiple times, place a cup of water inside cabinet, run for 30 seconds (do this multiple times switching out cups of water) and it works.

Return microwave to owner, owner uses for one evening several times, no issues. Tries to use in morning - dead. Assumption is that last operation of microwave in evening blew fuse without owner noticing.

Pick up microwave, find blown fuse, test switches again. Switches test proper. No visible signs of excessive heat or problems, no components test failed or shorted. Close up microwave, connect to power, run for 30 seconds with cup of water inside, open door, close door, run for 30 seconds again, open door, close door - FUSE BLOWS.

Has to be a door switch - test all switches, again. This time I use an analog meter to see in real time when switch opens and closes. ALL switches work without delay. Power relay contacts are in OPEN position, as they should be.

3 mechanical switches and one electrical relay involved with the door function:

- Primary interlock switch

- Secondary interlock switch

- Monitor switch

- Power relay on main PCB

​I am at the point now where I am assuming that the circuit board is intermittently glitching causing the power relay contacts to CLOSE when the door is closing. This would cause a direct short and blow the fuse (I tested this by disconnecting the power, disconnecting the leads form the power relay, putting a jumper across the leads to simulate CLOSED contacts of power relay, and then closing the door with a meter connected between L1 and N - meter goes to 0 ohms/dead short). But I can't prove it under power which is why I am hesitant to just throw parts at it to attempt a fix.

3 switches = $60.79 CDN before tax and shipping

PCB = $128 CDN, out of stock

Parts found here:

https://www.partstown.ca/panasonic/ne-10...

I could risk $60.79 on switches that appear to be working just fine or $128 on a PCB ( if I can actually get one) that I can't guarantee is the source of the problem. No smoking gun and no desire to waste money.

Any suggestions for troubleshooting this issue further? Thank-you

⟐ Commented dicembre 13, 2025 at 14:44 GMT-7