My display is very irratic and sometimes the power is cutoff and i have to turn the breaker off to reset

https://georgebrazilplumbingelectrical.com/blog/heres-why-your-microwave-keeps-tripping-the-circuit-breaker https://removeandreplace.com/2015/09/22/microwave-oven-shuts-off-after-2-or-3-seconds-how-to-fix/
https://removeandreplace.com/2018/03/15/microwave-oven-keeps-tripping-the-breaker-what-is-causing-this/

well inside the unit check for any burn fuses on the power supply area, and into the control board. fuse basically the one will tripped if power surged occurred..

I am not sure this is your issue ... but from the Whirlpool web site .. to turn demo mode off: Possible Solutions

The control has been placed in demonstration mode

IMPORTANT: This feature is intended for use on the sales floor with 120 V power connection and permits the control features to be demonstrated without the oven turning on. If this feature is activated, the oven will not work.
1. Press SETTINGS/CLOCK until "DEMO MODE" is displayed.
2. The current setting will be displayed.
3. Press the "1" keypad to adjust the setting.
4. Press START or CANCEL to exit and display the time of day.

Reset power to the product:

There may be a problem with the User Interface/Keypad, or the associated wiring.

• Power unit down by turning off the circuit breaker(s) for one (1) minute.
• Power unit up by turning on the circuit breaker(s).
• Monitor the oven for one (1) minute to ensure the error code does not display again.
• Verify oven operation.

There are few reasons for this fault, but the main is that you need to open your microwave oven and first check the Fan which is connected at the back which cools the magnetron.
If this fan fails thus results in magnetron being overheated and the thermal cutoff gets open circiut and shuts down whole power of your microwave oven.
Check your fan motor test it straight with direct power
Also check the thermal cutoff.

Let me know after you have done those checkups



Regards
Ashwin

Yes, it can be a fuse (usually a 20-amp fuse), or it can be a thermal cutoff device (called a TCO or thermostat) that is usually located above the cooking cavity (under the outer panel).

If you need further help, reach me via phone at https://www.6ya.com/expert/ronald_e6b9572cebe3ad27

You haven't said how long you cut power for when you flipped the breaker. These things sometimes have heavy capacitors in them taht will take a time to discharge and allow everything to reset. Before you call a service tech, unplug the unit (or flip the breaker, whatever) and leave the unit disconnected for half an hour. This may just be all you need to do.

Does the oven's key pad seem to reset like a breaker flipped inside? And after, you have to reset the clock? If so, check the temperature cutoff switches inside. Jumper across them and see if your microwave starts working correctly. I had this problem and the Bottom TCO was defective.

• Make sure that the microwave is plugged into a grounded outlet. It must be a 3-prong outlet.
  
• Make sure the clock is set.
• Check to see if a programming sequence was entered. Sometimes improper programming or a program sequence such as delay start can cause the touch panel to be non-responsive. Unplug microwave or turn off house circuit breaker for 30 seconds. Plug back in, or reset circuit breaker, and try reprogramming unit.
  
• Check the house circuit breaker or fuse box. If the microwave is DEAD and there is no display and nothing works- the problem could be a blown fuse or tripped breaker.

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;//www.ebay.com ) or purchase a new one.

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

Sometimes a glitch on the power line can scramble an electronic device, and the way to reset it is to interrupt power a few seconds then turn it back on.

I wouldn't worry as long as it;s not exhibiting other symptoms.