Question about Microwave Ovens

1 Answer

The (B) button is faulty, either need to change due to faulty spring, also might need a new circuit board. The (B) button is sticking, does not switch off. Please advice. Thank you.

Posted by on


1 Answer

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points


    An expert that got 10 achievements.


    An expert that got 5 achievements.

    Vice President:

    An expert whose answer got voted for 100 times.

  • Master
  • 472 Answers

Not sure what brand you are dealing with here,,,nut most units have a control board and then over the top is a overlay with the buttons that has a ribbon cable that goes to the control...may be something simple as the overlay has failed due to ormal wear and tear... all should be accessible right from the front and the console will come off either by removing a few phillips screws and lifting up out of slots and disconnecting a few wires...make sure to uplug the unit don't want to accidentally make contact with metal and cause more problems or a hospital visit....
good luck to you .....pleae vote.

Posted on Jan 03, 2011


1 Suggested Answer

  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

A 6ya expert can help you resolve that issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
The service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.
Good luck!

Posted on Jan 02, 2017


Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

1 Answer

Viewing screen lights okay. None of the buttons function.

You probably either have a bad connection between the touch pad and the main circuit board, or a component failure on the main circuit board.

Whenever I come across something like this, I always check the door switches for proper operation. Some ovens will not program if they have a switch failure.

Unless it's a door switch, or something else that's inexpensive to fix, I would suggest buying a new oven. 17 years old is quite old. Even if not used much, some components will fail simply due to age.

May 19, 2016 | Microwave Ovens


Troubleshooting Guide

  • Problem: Totally dead oven.
    Possible causes:
    1. No power to outlet (blown fuse or tripped breaker or GFCI).
    2. Blown main fuse - likely due to other problems.
    3. Open thermal protector or thermal fuse.
    4. Defective controller or its power supply.
    5. Clock needs to be set before other functions will operate (some models).

  • Problem: Totally dead oven after repair.
    Possible causes:
    1. Cabinet screws replaced in incorrect location (safety interlock not engaged).
    2. Any number of screwups. :)

  • Problem: No response to any buttons on touchpad.
    Possible causes:
    1. Door is not closed (some models).
    2. You waited to long (open and close door to wake it up).
    3. Controller is confused (pull plug for a minute or two to reset).
    4. Defective interlock switches.
    5. Faulty controller or its power supply.
    6. Touchpad or controller board contaminated by overenthusiastic cleaning.
    7. Defective/damaged touchpad.

  • Problem: Oven runs when door is still open.
    Possible causes:
    1. Damaged interlock assembly.
    2. Cooling fans (only) running due to bad sensor or still warm.

  • Problem: Oven starts on its own as soon as door is closed.
    Possible causes:
    1. Defective triac or relay.
    2. Controller is confused (pull plug for a minute or two to reset).
    3. Defective controller or its power supply.
    4. Touchpad or controller board contaminated by overenthusiastic cleaning.
    5. Defective/damaged touchpad.

  • Problem: Oven works but display is blank.
    Possible causes:
    1. Defective controller or its power supply.
    2. Broken display panel.
    3. Oven needs to be reset (pull plug for a minute or two to reset).

  • Problem: Whacked out controller or incorrect operation.
    Possible causes:
    1. Previous or multipart cook cycle not complete.
    2. Controller is confused (pull plug for a minute or two to reset).
    3. Defective controller or its power supply.
    4. Touchpad or controller board contaminated by overenthusiastic cleaning.
    5. Defective/damaged touchpad.
    6. Defective sensor (particulalry covection/mirowave combos).

  • Problem: Erratic behavior.
    Possible causes:
    1. Previous or multipart cook cycle not complete.
    2. Bad connections in controller or microwave generator.
    3. Faulty relay - primary (or HV side, much less commonly used).
    4. Defective controller or its power supply.
    5. Bad contacts/connections on mechanical timers. Intermittent fuse.
    6. Power surge at start of cook cycle confusing controller.
    7. Microwave (RF) leakage into electronics bay.

  • Problem: Some keys on the touchpad do not function or perform the wrong action.
    Possible causes:
    1. Touchpad or controller board contaminated by overenthusiastic cleaning.
    2. Defective/damaged touchpad.
    3. Controller is confused (pull plug for a minute or two to reset).
    4. Faulty controller.

  • Problem: Microwave oven does not respond to START button.
    Possible causes:
    1. Defective START button.
    2. Faulty interlock switches.
    3. Door is not securely closed.
    4. Faulty controller.
    5. You waited too long - open and close door to wake it up!

  • Problem: No heat but otherwise normal operation.
    Possible causes:
    1. Blown fuse in HV transformer primary circuit or HV fuse (if used).
    2. Bad connections (particularly to magnetron filament).
    3. Open thermal protector or thermal fuse.
    4. Open HV capacitor, HV diode, HV transformer, or magnetron filament.
    5. Shorted HV diode, HV capacitor (will blow a fuse), or magnetron.
    6. Defective HV relay (not commonly used).

  • Problem: Timer and light work but no heat, cooling fan, or turntable rotation.
    Possible causes:
    1. Defective (lower) door interlock switch or door not closing fully.
    2. Faulty relay or triac.

  • Problem: Fuse blows when closing or opening door:
    Possible causes:
    1. Defective door interlock switch(s).
    2. Interlock switch knocked out of position.
    3. Misaligned door.

  • Problem: Loud hum and/or burning smell when attempting to cook.
    Possible causes:
    1. Shorted HV diode, magnetron.
    2. Burnt carbonized food in or above oven chamber.
    3. Shorted winding in HV transformer.
    4. Frayed insulation on HV wiring.

  • Problem: Arcing in or above oven chamber.
    Possible causes:
    1. Burnt carbonized food deposits.
    2. Exposed sharp metal edges.

  • Problem: Fuse blows when initiating cook cycle.
    Possible causes:
    1. Defective interlock switches or misaligned door.
    2. Shorted HV capacitor.
    3. Shorted HV diode.
    4. Shorted magnetron (probably won't blow main fuse but HV fuse if used).
    5. Defective triac.
    6. Old age or power surges.
    7. Defective HV transformer.
    8. Short in wiring due to vibration or poor manufacturing.

  • Problem: Fuse blows when microwave shuts off (during or at end of cook cycle).
    Possible causes:
    1. Defective triac (doesn't turn off properly).
    2. Defective relay.
    3. Shorting wires.

  • Problem: Oven heats on high setting regardless of power setting.
    Possible causes:
    1. Faulty primary relay or triac or HV relay (not commonly used).
    2. Faulty controller.

  • Problem: Oven immediately starts to cook when door is closed.
    Possible causes:
    1. Shorted relay or triac.
    2. Faulty controller.

  • Problem: Oven heats but power seems low or erratic.
    Possible causes:
    1. Low line voltage.
    2. Magnetron with low emission.
    3. Faulty controller or set for wrong mode.
    4. Stirrer (or turntable) not working.
    5. Intermittent connections to magnetron filament or elsewhere.
    6. Faulty primary relay or triac or HV relay (not commonly used).

  • Problem: Oven heats but shuts off randomly.
    Possible causes:
    1. Overheating due to blocked air vents or inoperative cooling fan.
    2. Overheating due to bad magnetron.
    3. Bad connections in controller or microwave generator.
    4. Faulty interlock switch or marginal door alignment.
    5. Faulty controller.
    6. Overheating due to extremely high line voltage.
    7. Stuck stirrer fan resulting hot spots detected by sensors.

  • Problem: Oven makes (possibly erratic) buzzing noise when heating.
    Possible causes:
    1. Fan blades hitting support or shroud.
    2. Vibrating sheet metal.
    3. Vibrating transformer laminations.
    4. Turntable or stirrer hitting some debris.

  • Problem: Oven light does not work.
    Possible causes:
    1. Burnt out bulb :-).
    2. Bad connections.

  • Problem: Fans or turntables that do not work.
    Possible causes:
    1. Gummed up lubrication or bad motor bearing(s).
    2. Loose or broken belt.
    3. Bad motor.
    4. Bad thermostat.
    5. Bad connections.

on Mar 30, 2008 | Kenmore 80412 Microwave Oven

2 Answers

We have an Akai A24005 Microwave. Its hardly been used it lives in our guest cabin and it just stopped working. The dial lights up, the light comes on when you open the door but it won't cook

Good day: The door switch is not contacting properly due to the lever that contacts the switch being loose(probably a screw that was not tightened properly during assembly at the factory, or even the screw that secures the switch unit itself might be loose causing play, that is why when you pull at the door it works. Just take it to an ordinary appliance repair shop and they should be able to fix it without too much effort and retain your receipt and present it to the agents challenging them on their failure to provide service when they should have, thereby forcing you to seek other assistance as a last resort, and hopefully they will not void the initial warranty that normally comes with a new appliance. (Warranty states that no one other than the agents are allowed to repair the machine during the warranty period).
Good luck.

Sep 09, 2014 | Akai A24005B Blue Countertop Microwave 20...

1 Answer

Micro wave display too weak to read. How difficult is replacing circuit board on Jenn Air Model jmv8208bas ?

Possible that the display unit or the main processor unit is faulty; It is possible that insects could have nested within and produced accumulation of dirt within the circuits to dampen and short the circuit. Remove front panel and clean , use dryer to warm. If the fault persists it can be due to faulty or weak LCD.

Jan 21, 2013 | Microwave Ovens

1 Answer

Runs down to 1 min. then runs forever .I have to shut it off manualy

Possible that the main program controller unit is not shutting down due to the relay being latched ON even after the time is finished.
You need to check if the processor cuts off the relay and still if the relay holds down, If so the relay drive transistor or the relay is faulty.
Also it can be fault of the program processor/timer as it fails to cut off the relay drive. If so check the circuit, wash the board if you find insects secretion. Also try to solder the processor and associated circuits and try again before the board is confirmed as a suspect.
take estimate and decide.

Jul 12, 2011 | Microwave Ovens

1 Answer

I get h97 display in microwave cd997s what is remedy

Faulty Magnetron or Power supply for it.

DO NOT try to REPAIR this Inverter Power Supply (U) and also DO NOT RE-ADJUST PRESET VOLUME on the board. It is very dangerous to repair or adjust without sufficient test equipment because this circuit handles very high voltage and very large current. Off alignment or inverter board operation is dangerous. Operating a misaligned inverter circuit is dangerous due to the very high voltage and current that is produced by this board. Defective boards must be replaced with a new one.
Consult an approved Panasonic Microwave Repair Service.

Jan 13, 2011 | Panasonic Microwave Ovens

2 Answers

Controlpanel flashes f 3

You have a faulty keypad. You could probably special order this part from a local appliance parts supply store for 50-60$ or purchase a new microwave.

Oct 22, 2009 | GE Spacemaker JVM1640SJ Microwave Oven

2 Answers

I have a National Panasonic Genius microwave that doesn't work the last four days. It won't heat, defrost, microwave or cook.Worked fine one day. Next didn't. All I had done was change the temp from high...

That fault is a little tricky. Need to check if you are getting voltage onto primary of transformer. If you are, the problem is almost certainly the magnatron which has gone open circuit. If and when you replace it, change the cap and HVdiode. Wont be sorry if you do. If no voltage there , your board is faulty. replace it.

Sep 15, 2009 | Panasonic NN-H275 Microwave Oven

2 Answers

Electric went out to the house, it came back on, and the microwave inside light works, the display panel reads just a " : ", and none of the buttons work. I have tried resetting the breaker with same

Hi cschnur,
     It seems that you might need to replace circuit board.
All the above mentioned conditions refers to a faulty circuit board. You might have blown few Ic's.
Take a voltmeter, check the continuity. If you are aware of the Ic's, replace them.
Unless, look for a tech, a used board ( On http;// ) or purchase a new one.

Thanks for using Fixya.
Do rate the solution as "Fixya" if 100% satisfied.

Apr 17, 2009 | Kenmore 63682 / 63684 / 63689 Microwave...

1 Answer

Door sticks

This is usually due to a grease buildup on the sides of the door open button or the frame that holds it.

It may also be a weak door button spring.

You'll need to remove the cover to see how the door open button works.

You can order parts here.

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

Jun 04, 2008 | Microwave Ovens

Not finding what you are looking for?
Microwave Ovens Logo

Related Topics:

17 people viewed this question

Ask a Question

Usually answered in minutes!

Top Microwave Ovens Experts

William Miller
William Miller

Level 3 Expert

9098 Answers

Donald DCruz
Donald DCruz

Level 3 Expert

17130 Answers


Level 3 Expert

78919 Answers

Are you a Microwave Oven Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides