UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post

FrankB · 1st May 2021, 10:16 am

Discharge HV cap & remove magnatron wires Ohm the magnatron filament to ground and the HV conn to ground. If it shows leakage, mag is bad. You can ohm the diode for a short, as well as the capacitor for shorts.
Once in a blue moon you can get a shorted transformer. Think I have seen 2 in the last 30 yrs.
Growling is a major short. I would guess mag or diode, off my hat.
Be sure to clean any grease out of the wave guide and as was said, clean or replace mica. Arcing to metal can be repaired by sanding it then using the special microwave oven paint. Works quite well. Clean door seals as well and beg, borrow or steal a microwave leakage tester.

1st May 2021, 10:16 am	#25
FrankB Heptode Join Date: Oct 2005 Location: Olympia, Washington, USA. Posts: 664	Re: 32 year old Sharp microwave oven... Discharge HV cap & remove magnatron wires Ohm the magnatron filament to ground and the HV conn to ground. If it shows leakage, mag is bad. You can ohm the diode for a short, as well as the capacitor for shorts. Once in a blue moon you can get a shorted transformer. Think I have seen 2 in the last 30 yrs. Growling is a major short. I would guess mag or diode, off my hat. Be sure to clean any grease out of the wave guide and as was said, clean or replace mica. Arcing to metal can be repaired by sanding it then using the special microwave oven paint. Works quite well. Clean door seals as well and beg, borrow or steal a microwave leakage tester.