Panasonic NNA554W blows 10a fuse when microwave comes on
There was a bang in the middle of the night and found 10A fuse blown in microwave in morning. Replaced it and timer came on ok but as soon as microwave powered up fuse blew again. What are the most likely candidates for causing this problem?
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Re: Panasonic NNA554W blows 10a fuse when microwave comes...
Possibly the interlock monitor switch is bad or out of adjustment. This switch is designed to create a short circuit across the power line (and then blow the fuse) if you attempt to defeat the door interlock and operate the oven with the door open. A shorted capacitor or diode could also cause the fuse to blow. Because of lethal voltages inside and the possibility of microwave leakage if repairs aren't done correctly, you are best off leaving microwave service to professionals.
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no 3rd fuse as far as i know just the two on the mains pcb and the plug i would test all three fuses again but if the short has gone back up to the control panel them that might be why its not coming back on if it has blown the control pcb it will show up as ablack mark on the pcb sorry cant be nore help its the sort of thing i would need to see as it could be a door micro switch as well gd luck dont forget to unplug the unit
Check continuity of this 10A fuse to see if it's blown.
What is most likely to have happened, is that an internal short has happened inside the main transformer. These cannot be rectified, and often means scrapping the complete item due to cost of replacement.
However - if you can find another microwave with a different fault - just remove the good transformer.
Checking the transformer for a short at high voltage is not recommended.
You could try a spare 10A fuse as a start point (probably a leaded type) - but expect it to blow again. DON'T go higher or omit !
never put higher fuse then what is already there can cause a fire microwave are being made more disposable now either use warranty or buy a new one i am lucky if i get one to last a year before it starts acting up cheaper to buy new one then to have it repaired
error 81 message is usually a fault in a relay....found on the LV transformer located beneath the noise filter....(noise filter is a ciarcuit board mounted to one side, should see 2x 10a fuses on it and a small 1.25A)...underneath, a circuit board...thats the lv transformer assy.
Check the 10A fuses first....if they are ok, change the entire transfromer assy.....easy enough to do, the part number is A692M3310GP
sound like the door monitor switched has blown or shifted out of position if the switches dont operate in tandem when door is opened or closed it will blow the 10 amp fuse and kill the display they will need to be checked by engineer if it is monitor switch they are not expensive to replace.
If the diode failed by opening, there may be no other damage. If the dioded failed by shorting, the alternating current may have damaged other components. Ohm it out. You can get diodes from digikey.com, mouser.com, or radio shack or any electronics or appliance supply. If the diode is charred and you can't get the part number, the oven rating can be used to select a replacement. Since the fuse was 10 amps, the diode should also handle at least 10 amps. If you can power the unit and read the voltage at the diode input this will give you the power (volts times amps). It's always worth trying as it's cheaper than replacing the unit.