Panasonic microwave, where is the capacitor??

[theflyingpig]

I need to discharge the capacitor on this machine (Nn-ct552w) before I can replace a faulty door switch... There's alot more going on inside this machine than I've seen before - usually the capacitor is obvious!
Anyone know where it is?

 

[Jurassicspark]

Looks like its all on a circuit. No bulky transformer and capacitor.
Still does mean it will need discharging.

 

[theflyingpig]

Hmmm. So how do I discharge?

 

[RandomGrinch]

Apparently you have a Panasonic Inverter microwave.
The spare part listed is...

The green caps on the bottom are the high voltage ones.

The usual caveat, for anyone visiting this thread - the high voltage generated within a microwave can be lethal, and the high voltage capacitors can store a charge, even after the power has been removed (although there are bleed resistors).

DO NOT mess with the insides of a microwave, if you don't know what you are doing and don't know where the dangers lie.

 

[Doug99]

If it is only the door switch you are touching, I would short out the switch cables to chassis before fitting, and keep fingers away from the magnetron circuitry.

 

[old duffer]

My very first assignment at Uni was on the operation of a microwave......just take an uninsulated long screwdriver or metal bar and just probe about...you will soon discharge it...

 

[Jurassicspark]

My very first assignment at Uni was on the operation of a microwave......just take an uninsulated long screwdriver or metal bar and just probe about...you will soon discharge it...

could damage the capacitor that way not really ideal.

 

[theflyingpig]

OK. Got the door switch mechanism out. Not without a few choice swear words I have to say!
It's got three switches. The top one I unfortunately broke whilst pulling the cable plug of it.... The other two test for continuity - one in the normally open position, the other in the normally closed...
No sign of any burning around switches....
I either buy a replacement for the top switch on the assumption it was faulty, or scrap the machine....

 

[RandomGrinch]

I either buy a replacement for the top switch on the assumption it was faulty, or scrap the machine..

It's probably worth trying? It looks to be a standard microswitch and would only cost a couple of pounds.

 

[theflyingpig]

Yes, I'll give it a go....

 

[theflyingpig]

But, how do I know if it's normally open or normally closed?...

 

[Jurassicspark]

But, how do I know if it's normally open or normally closed?...

usually there will be a diagram on the switch showing whether its a nc or no switch.

 

[assuhors]

Two are normally open and one normally closed.The monitor switch is normally closed and this gets opened on shutting the door before the two latch hooks close,the internal fuse will blow if the sequence isn't followed.

 

[theflyingpig]

Door switch replaced. Machine appears to be working as it should. A rare win!