• ** REMEMBER! **The microwave can still shock you even unplugged!!

    ALWAYS discharge the high-voltage capacitor first if you even think your hands will come close to any HIGH VOLTAGE components.

    Jeff mentions this: Anything in the high voltage ( magnetron, capacitor, diode, wires to and from ):
    ...Use a metal ( not the shiny chrome type ) screw driver with a insulated handle to short across ( touch both at the same time ) the terminals of the high voltage capacitor to discharge it.

    From Jeff's site: http://www.applianceaid.com/component-testing.php

    Jake

DPC fuse blown on Panasonic

david11

New member
Joined
Feb 22, 2011
Messages
1
Location
UK
Model
NN-A574SBBTQ
Brand
Panasonic
Age
1-5 years
Shut the door and load bang- dead microwave. Thought it might be a door latch switch or main fuse but these are all ok. Found that pf1 on DPC- DU has vaporised leaving black smudge (on pcb 'danger line voltage area'). Similar report here:
http://www.siliconchip.com.au/cms/A_101933/article.html


Have service manual and their suggested checks: have checked pf2 is ok, ZNR varister looks ok (no burns) - but I don't know how to test, lamp blew a while ago and checked that not currently shorted, 'windings resistance on low voltage transformer primary coil ' is 287ohms (this is an omron g5g-1A-12vdc where terminal attach to dpc pcb - tested two units ry1 and ry4 - both had same resistance and agrees with specification sheet for omron within 1 ohm)
There is also a capacitor just past pf1 that has a round mark about 5 mm across (?paint rubbed/burnt off) so I'll probably try replacing /testing that

Can I repair pf1? I might put an ammeter across this to check what fuse rating I need but if fault still exists I'm worrying I'll do more damage!

Any ideas what else to check? (I'm thinking it was bulb)
Thanks
David

 
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