0.036uF shorts in Microwave inverter.

[Russell Griffiths]

Panasonic microwave model NN-S769WA.

Inverter type oven.

C705 (0.0036uF 3kv) was shorted (it had a hole blown in it).

I bought 2 of these from WES (replaced both C705 and C704).

Turned oven on and the new C705 burst.

I hate inverter microwave ovens!
Give me an old fashioned transformer type any day.

The only other Inverter type I repaired needed both
the transistors and the rectifier.

Could a faulty magnetron cause this?
It is not shorted to ground.

Can anyone please assist?

Is the complete inverter available?
Where from?

Thanks,
Russell Griffiths.

 

[Rudolf Ladyzhenskii]

Hi,

I can not recall this model, but check diode off the capacitor.
Rudolf

"Russell Griffiths" <rg26ce1991@hotmail.com> wrote in message
news:13cdb672.0402151953.595eeb37@posting.google.com...

Panasonic microwave model NN-S769WA.

Inverter type oven.

C705 (0.0036uF 3kv) was shorted (it had a hole blown in it).

I bought 2 of these from WES (replaced both C705 and C704).

Turned oven on and the new C705 burst.

I hate inverter microwave ovens!
Give me an old fashioned transformer type any day.

The only other Inverter type I repaired needed both
the transistors and the rectifier.

Could a faulty magnetron cause this?
It is not shorted to ground.

Can anyone please assist?

Is the complete inverter available?
Where from?

Thanks,
Russell Griffiths.

 

[Russell Griffiths]

"Rudolf Ladyzhenskii" <rudolfl@optusnet.com.au> wrote in message news:<403070a7$0$5224$afc38c87@news.optusnet.com.au>...

Hi,

I can not recall this model, but check diode off the capacitor.
Rudolf

"Russell Griffiths" <rg26ce1991@hotmail.com> wrote in message
news:13cdb672.0402151953.595eeb37@posting.google.com...

Thanks Rudolf.
The cap. involved (C705) has one side connected to ground, the
other lead connects to one terminal of the transformer and one lead
of the other 0.0036uF (C704). The other lead of C704 connects to
4 things:-
1 - One of the magnetron terminals.
2 - Anode of D701 (UX-C2B).
3 - Another of the transformer terminals.
4 - R701 (This is labelled "207P", I assume this is 200,000,000 ohms).

The Cathode of D701 connects to the Anode of D702 (UX-C2B).

The junction of the two diodes connects to another
of the transformer terminals.

I tested both the UX-C2B diodes with a 22 volt supply and a
270ohm R in series. I measured about 8 volts across both diodes.

Can anybody suggest anything else?

Thanks,
Russell Griffiths.