Advantium microwave smart board replacement help needed

[tgoods]

Check the primary side of the HV transformer for voltage.  Since this is a 240 vac microwave, I don't know if you should read 120 vac or 240 vac to the transformer.  But, it should read one or the other.  If no voltage, the problem is on the low voltage side; fuse, control board, tco or door switch. If there is voltage, the problem is on the high voltage side; HV transformer, HV capacitor, HV diode or magnetron.

[kludge]

Excellent guidance, Tgoods... that's exactly the kind of advice I'm needing.

Checking those voltages with the smart board connected will be pretty difficult though, with 10 cables in the way.  Can I disconnect the smart board and still get accurate readings off the transformer?

[RegUS_PatOff]

have you tested the HV Diode and the HV Capacitor ?

[tgoods]

Is there a tech sheet?  GE usually has it stashed around the control board somewhere.  I downloaded the same manual you did but it's for the 120v Advantium not 240v.  I did a reverse lookup on the HV transformer and it only fits the 240v Advantium models.  So, I assume the transformer primary voltage should be 240 vac. If I had a schematic, I could give better advice.

[kludge]

Here it is.  It appears that the Interlock Monitor Switch is in a very important location.  I guess it should be the first thing I check.

[RegUS_PatOff]

... It appears that the Interlock Monitor Switch is in a very important location.  I guess it should be the first thing I check.

no, that's a safety switch that, if stayed "closed" would blow the Fuse,
if stayed "open", the M/W would still work.
 

have you tested the HV Diode and the HV Capacitor ?

[kludge]

If this were a $500 microwave, I would just replace it and be done with it.  But it's a $1300 unit...and a HUGE job to de-install and re-install a new one.  So my question to any of you very kind experts is...

When I tear it apart again, which components should I replace that would pretty much guarantee that it would microwave again?

Please look at the schematic above, and note that I've replaced the Main PCB, and that everything works but the microwave function...and tell me what parts to replace.  I figure $500 worth of parts replaced, even if some weren't bad, is still a worthwhile investment, all things considered.

And again..thanks Very Much for your guidance thus far!!!

[RegUS_PatOff]

have you tested the HV Diode and the HV Capacitor ?

[kludge]

have you tested the HV Diode and the HV Capacitor ?

No.  You are an expert.  I am not.  I do not relish the idea of using test leads inside a 220v appliance while it is energized.  I know it's pretty foolish to replace perfectly good components... but I would rather replace a transformer that didn't need replacing than risk frying myself and/or the appliance.  If you are quite confident that it is the diode and capacitor in the HV section that has failed...then I will replace them.

[RegUS_PatOff]

Capacitor can be tested without power using an OHM meter.
Diode can be tested using a 9v battery and an OHM meter.

[tgoods]

Interesting schematic.  Even though it's a 240 volt microwave, all of the components are 120 volt.  If your cooling fan and turntable work, you know you have power to that point.  Check for 120 vac from the blue wire at the fan relay to the red wires on relay2 on the control board.  If you have power there, you should have power to the HV transformer unless there is a break in the wire. If no power, check for 120 vac from the fan relay to the primary interlock switch.  It's the door switch with red wire and a brown wire with a yellow stripe. If you have power to the HV transformer, the problem has to be on the high voltage side.  Check your high voltage components. Unplug the microwave and discharge the HV capacitor.  Check the primary winding and both secondary windings of the HV transformer for continuity. You can check the HV diode with a 9 volt battery, you should read voltage in one direction and 0 in the other.  Check the HV capacitor with a capacitor checker.  If you don't have a cap checker use the resistance setting of your meter, you should see a jump in resistance that then immediately rises to infinite. If not, reverse the leads and try again.  The magnetron should have less than one ohm resistance between the two terminals and infinite to ground.  If everything checks good, replace the magnetron.

[JWWebster]

I have seen a 220v microwave but it was commercial model with 2 mag's in it. It was used at fast food rest to heat. This one is the weirdest yet I have seen. Might just be a bad mag. It ain't shorted but it could be open. And since all microwaves basically come from the same source and that single one is getting a higher amp draw with the 220 source , I would be checking for continuity between the two terminals on the mag. Could be wrong. Have been before