Blowing Fuses I have a 1993 - 2000 Panasonic "the Genius" Microwave, and it has suddenly started blowing the fuse on the power supply card. I have replaced the 8A fuse with a 10A fuse, but that still blows. It was working fine up until yesterday, Please advise me as to what could be the problem, and how to rectify it. Regards Lyall Clifton

Are other appliances running on the same circuit? Does it happen in the summer with the A/C on?
It may be starved for voltage. I've seen this happen on homes where the beaker panel is undersized or has a loose connection.

Power supply is faulty

If it keeps blowing a fuse then there is something that is causing the current spike blowing the fuse. I would run a full diagnostic or ask a qualified electrician. Something else is most likely blown and replacing a fuse would probably just feed the problem.

time to take it to an appliance repair shop for a quote
it is blowing fuses and tripping breakers because it has a serious short in the electrics

I am wondering which fuse is blowing?
There are at least two fuses fitted internally and in the UK at least another fitted in the plug of the supply lead.

It isn't wise for an unqualified person to replace the internal fuses of a microwave even if it is switched off as there is a capacitor inside that is capable of storing a dangerous amount of energy.

The reasons why a fuse blows is either because there is a poor connection close by that is generating a lot of heat or the the fuse rating is incorrect or of the wrong type (quick-blow instead of slow-blow) or the appliance is consuming more current than it should be.

Microwave ovens have a fairly simple working principle and there aren't many things to go wrong. When things do start to go wrong or components become tired it is usually translated into a loss of efficiency that can be measured by how long it takes to boil a measured quantity of water, for instance.
Periodically timing a measured quantity of water to boiling point is a good way to monitor the performance of a microwave and when efficiency falls significantly take it to the service shop before something destroys itself and causes more damage.

In my limited experience the magnetron could be failing but the internals of a microwave should remain a mystery to the unqualified.
I hope this helps a little.

Mainly there are three/four fuses in Microwaves depend to maker.
First one to be checked it is on plug about 13A in cable out side microwave
Second one for power supply usually comes 10A located in terminal board of cable supply in side microwave if you follow the cable.
Third fuse i think about 5A for high voltage it located usually on wire connected between transformer and capacitor.
Fourth some Microwave have third one on the control board located behind switch panel.

now.

if the second fuse is blowing immediately after starting microwave that usually mean one or more of the following need to be replaced

1- diode
2- HV. capacitor
3- magnatiron

Which only can replaced by skill technicians

THANK YOU.

the microwave has a short in the power supply it can be the diode or the high voltage capacitor.have a tech check your microwave for repairs.good luck.

If it blows the line fuse instantly when you push start.... it is either a shorted HV capacitor or shorted monitor switch.... most likely.

In that case the outlet your using is pushing out too much electricity. Try calling your local electric company for help or a professional electric repair man.

If it went dead almost immediately after pressing the Start pad, that's usually a shorted high-voltage capacitor.

Here is a link you or someone you know can use to test it, but please read the safety info:
http://www.gallawa.com/microtech/cap_test.html

You can order Panasonic parts from Tritronics here or by calling 866-779-5835, but if you don't find what you're looking for there, try here.

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