It jus stopped working as soon as i set the timer to 3mins jus light switched on for a second and its gone,,,i checked the power output in the plug point its fine...no burning smell and all...this oven is 850 watt

Possibly a bad door switch behind the holes where the latch hooks go into. Usually with the bad switch the timer counts down but nothing runs. It all depends on which switch is bad. Usually 3 switches inside.

There are door switches and one of them is evidently out of adjustment or the little actuator arm on it is.

A 1974 Microwave Oven is probably not putting out more than 600 watts. You need to do a power test to determine it's actual power output. Place a 2 cup glass measuring cup with exactly 500 mL of cold water. Record the starting temperature of the water. Run the microwave on 100% power for 18 seconds, using a watch or timer, not the timer on the unit. Take the water out and stir it to make sure that there are no hot or cold spots in the measuring cup. Record the new temperature. Example: 78.4-64.1= 14.3.
Multiply 14.3 X 38.75= 554.125. The power output is 554 watts IEC. If the recipe is set for a 1200 watt unit, and your is almost 600 watts, obviously, you would double the cook time. Since this is rough, you need to experiment a bit. If the cook time is 10 minutes, check your product at 8 minutes. Be sure to push the stop button before you open the door when it is in cook mode. This will save wear and tear on door switches and leave the remaining cook time on the timer. Let me know how this works out for you..

The door switches are more than likely the problem, one or two will need to be replaced, I recommend a professional.

Just checked the GE website. Had the same problem with my 5 year old microwave. GE website says to close and open the door quickly three times. First time I did this it didn't work. Second time I closed the door with some significant force and reopened it more quickly. Worked. Unplugged the microwave, plugged it back in, still fine.

Sounds like you blew a device on the main board when you didn't unplug it first. The whole main timer board must be replaced to repair the unit. Pricey, sorry!!

hmmm...well..did you do a power setting? that is what is needed in the sequence just stated..try one of the presets like popcorn, to see if that works.

The high voltage power supply for the magnetron, or the magnetron, or the output drive from the logic uPC board may have failed. The service tech is able to test these areas by taking readings to determine where the fault is.

Jerry G.

you have a bad inverter board.

Chances are the oven is designed for 60HZ and your supply is 50Hz. This will cause the unit to shut down because it thinks it is not getting the proper "interrupt" signal from the power line. You can check the owner's manual (or model number tag) and the manual for the converter.