Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!gatech!mcnc!decvax!ima!haddock!kencr
From: kencr@haddock.ima.isc.com (Kenny Crudup)
Newsgroups: sci.electronics
Subject: Re: Microwave Oven Repair
Message-ID: <14551@haddock.ima.isc.com>
Date: 8 Sep 89 19:02:05 GMT
References: <10931@fluke.COM>
Reply-To: kencr@haddock.ima.isc.com (Kenny Crudup)
Organization: Interactive Systems, Cambridge MA
Lines: 45

In article <10931@fluke.COM> inc@tc.fluke.COM (Gary Benson) says:
>Last night my 4-year old Tappan microwave oven chattered, buzzed, and died
>in the middle of baking some potatoes.
>Continued jiggling resulted in half a rather large diode dropping out onto
>the rug.
>Does anyone out there have experience in repairing microwave ovens?

Yup. I used to fix 'em in a stereo place back where I went to school.

>If I open this unit up, what are the chances I am going to destroy the
>dimensions of a precisely formed cavity's geometries and wind up with a
>microwave cannon to the gonads instead of an oven?

Real small. The magnetron is coupled to the resonating area, and the whole
shebang is fastened to the 'oven' part. Most electrics are accessible without
messing with any of that. But- DON'T TOUCH THE FLUX CAPACITOR!! :-)

>Are there any special seals or safety interlocks to look out for and replace?

All the ones I worked on had nothing but an AC cutout on the back panel. No
seals, and all the i-locks are obvious (more AC cutouts). However- make
sure the geometric association reference modulated oscillator threshold
point is less than the residual charge current! (OK, OK, more bullshit,
sorry :-)

>Once inside, I should be able to find my way around the circuit ok, and if
>I go in, I would also want to check the klystron.

Yeah. I would wonder if the dead diode is the cause or the effect.

>So do you have any ideas on how to check the tube? Take it into the local
>appliance repair guy?
>Gary Benson    inc@tc.fluke.COM

I doubt they would do more than change it. Provided the mag is really the
cause, you can always 'smoke-test' the diode....
But anyway, these things are, for the most part, meant to be fixed by your
average appliance hack, so they are relatively idiot-proof, if you know
your way around a high-voltage circuit.

-- 
Kenneth R. Crudup, Contractor, Interactive Systems Co.(386/ix), Cambridge MA
						   Phone (617) 661 7474 x238
Bensonhurst, NYC - Howard Beach '89. Kinder, gentler huh? Right!!
{encore, harvard, spdcc, think}!ima!haddock!kencr      kencr@ima.ima.isc.com