6 replies to this topic

[bluefrog]

Hi all, I wanted to run this by some of you experts since my knowledge of microwaves is limited.  I have a double oven microwave that runs fine but no heat.  I removed the microwave unit from the oven and brought to shop for diagnose.  So far I have checked all fuses and the capacitor and they check fine.

 

Tested diode and it drops to 6V on a 9volt battery and reads mV when reversed. 

 

I tested the magnetron terminals and they both had resistance of less than 1 ohm, also checked from terminal to mag body and showed infinity.  It looks as though the magnetron is ok.  Is this a foolproof test?

 

I didn't really know how to test the transformer and I can't power the unit on without it installed in the double oven.

 

Any thoughts out there?

 

Thanks,

Nick

 

 

 

 

[Cactus Bob]

The ohms test is no way to test a magntron , all your testing is the filament , and most bad magntrons have good filaments 

 

i always thought the ohms test was stupid , but i guess it's the only way to test the thing

 

my rule of thumb : check everything else , if it's all good and you still have no heat , replace the magntron . i have been right 100% of the time

 

I am lucky , i have a bunch of used "test" magntrons , to just switch it out and see what happens

 

just so you know , magntrons are all wired the same inside , as long as you can mount the mag even if it's just 2 screws , you can use it to test for heat .  just use your head and be sure to mount it with a good seal and don't leave an incorrect one on for more that a few mins while testing

[RegUS_PatOff]

and the the original problem was no heat ?

(not a blown Fuse) ?

[bluefrog]

Thanks for the reply!  

 

Yes original problem was no heat, and I the ceramic and thermal fuses check out ok.

[jumptrout]

Why can't you make a test cord to power the M/W?

[Samurai Appliance Repair Man]

The ohms test is no way to test a magntron , all your testing is the filament , and most bad magntrons have good filaments 

 

Check out the Willie Method™ for testing a magnetron ==> http://appliantology...magnetron-tube/

[Chat_in_FL]

Why can't you make a test cord to power the M/W?

No model number here, but a test cord to the primary side of x-fmr to by-pass door switches, relays, etc...  and if your diode and cap check out OK, narrows it down to the mag if no heat.