Sunbeam SM777 700 WATTS

There could be a problem with your microwaves switchboard.Or the wiring connection is not good and causes it to heat up and causes the fuse to trip and then has the power shut off for your microwave.

Could be the magnetron or the transformer. No it is not worth repai

for safty resons dont use it till you have it fixed
if there is microwave enegy flying around and it hits you you could get burnt badly

Magnetron and diode most likely. Need more info.

If you have an item overheating, try looking at the directions on the unit for the watts and adjust cooking time according to the oven. Some foods will explode if left for too long in a quick heating microwave oven. If this is a new problem and the microwave is 4 years old, you may consider the unit is beyond its useful life. Its difficult to tell w/o knowing the brand, but it could be the meagtron tube is simply wearing/worn out. Let me know if this helps. m

There is a short in the cntrol board. I have seen problems arise like this from mice, spiders and other insects. Power fluctuations can also trick the control into activating. ERIC

you have either a bad keypad or control board.

If you have operation of some buttons and not others its the keypad. if you have no operation out of the buttons at all you have a bad control board.

If you turn your microwave on and it sets and the timer counts down you have a bad interlock switch..

please let me know exactly what your microwave does when you set the cook time

The "main" relay on the control circuit board is stuck (shorted) and needs to be replaced.

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

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.

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

first of all your mwave needs to be properly ventilated .the problem is your magnetron when heated the thermal cutof switch cutts out power to magnetron.works again when cool.change magnetron