Small Household Appliances/microwave blows fuse


Hi Have a Panasonic Genius Dimension 4 (240volt) which blows fuse when plugged in and switched on. No bang or smell. Tested capacitor-OK, diode  2x062H (SK 1024l), this one bridges the two terminals of the cap, using the 9v battery test in both directions show 0.02 v (? thinks this maybe is culprit) and diode hvr-1x 4 (sk 1n28) this one is to ground and cap, shows good volts in one direction and near nothing in other, magnetron has a very faint click when shaken similar to micro switch click ( is this suppose to be 100% quiet?), nothing else out of the ordinary.
I have never troubleshot a MW oven before so this was a new learning curve.
thanks in advance for any advice, dont what to biff this as its a top shelf made Japanese unit and has been faultless since about 1990

You have a direct closed circuit somewhere to be blowing the fuse.  If you have any flow through the diode, it will cause this symptom. Most diodes are also resistors but only in one direction. Also if the mag tube is internally shorted it will cause the same thing and there is no really good test for a mag tube. If it rattles, that is a bad sign.  Usually if a door switch is bad it will not work but not blow fuses.  

The only way it will be cost effective to repair the unit is if it is a diode as a mag tube will cost more than the oven.  We repair very few microwave ovens any more as they cost more to repair than replace.

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Wayne Kiefer


Any concerning the repair of small electric household appliances (coffee makers, waffle makers,etc.) shavers, antique clocks, air compressors, lamps, generators.


High school Industrial Arts teacher. Plant manager at Trek Bicycle factory. Self employed for last 20 years in the small appliance repair business.

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