Microwave just stopped working.acts like it has no power

If you are not sure in ANY way about using this microwave BUY a new one. Simple as that!!
As long there where no sparks, strange noises or strange smells you should be OK to use it. Most modern microwaves have safety electronics built in that can act as a safety switch.
You can buy 'Plug In' adapters that are designed as a safety circuit breaker. Try searching for "Plug through RCD adapter". These 'Trip' if there is a power surge stopping the power to the item plugged into it. I have one for when I use big power tools.

most of the time magnetron is not working and neeeds to be changed.

Any microwave over 10 years old is not worth repairing. The touch pad is failing and parts may not be available.

There is an internal fuse inside. Need to find the cause for it blowing or it will just go again. Check the monitor switch and door switches. Eric

Mostly with GE I find this to be bad connections at the fuse holder or a bad fuse due to a bad fuse holder. It will break connection and reset the unit when the connection gets hot and expands and then opens and stops power from getting to the unit.

I HAVE KENMORE 665/61629 LIGHT STAYS ON. AND DO NOT COOKS. AND THE FAN DOES NOT WORK.

Hi,
Here is a tip that will help you to figure out what is wrong with your Microwave Oven....

Microwave Oven Basic Troubleshooting Tips
http://www.fixya.com/support/r5508031-microwave_oven_basic_troubleshooting

heatman101

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.

The fault could be the power supply, safety door switches, or the main logic control board. Any one of these, or combination of these, can cause the oven to act like its dead.

Jerry G.

I would suggest that you try it for a minute or so on the very lowest power level and see if it shuts off. If so, please post again with more detail about how it fails, such as whether it loses all power as if someone unplugged it or just acts as if someone hit the STOP button.