Hello from JA My name is Woody. I will be glad to assist you today. I have been servicing ALL Major Brands of Appliances for 33 Years, and have over 100,000 in home repairs and over 50,000 phone and internet repairs under my belt.
May I have the FULL model number of the unit from the unit to better assist you ?
GE JKP90S; Serial # XXXXX 10046Q. I did get the unit removed, but how do I check teh tube?
JKP90S is not a Complete number !!
a complete number will look like this JKP90SM2SS with just JKP90S gives me 28 models that start with that number ,I need to get closer then 28 differant models .
To chech the Magnitron tube you will need to Ohm it out with a meter to see if it has continuity across the two leads and from either lead to ground.
Model J KP90S M2SS How do you access the magnitron? The access plate on teh bottom is for teh turntable, not the tube
if you aready have the unit out of the cabinet .
You will need to remove the outer cover sides /top three sided panel to gain access to the Magtube.
Most of the screws come from the rear !
one more question - the resistance to ground is 120 ohms on the magnitron. seems low, but not a dead short. Has continuity between leads (< 1 ohm).
You should have NO continuity to ground at ALL , that would mean the magtube is faulty ,if you are checking terminal to ground and get a reading !
here is a link to the part if you need it .