GE microwave Model PSB912OSFSS GE Profile 30 in. Single Wall Oven with Advantium Technology will run but not heat and you can hear arcing

[TINO15150]

Brand:GE
Model Number:psb9120sfss
Main Symptom: Micro wave will not heat and had arcing sound. replaced diode and the Transformer was still arcing. Replaced Transformer and it is still arcing and shorted out diode again

What happens & when:

Error Code (if any):
Parts or tests already tried: tested capacitor all microswitches on door latches. Checked fuses and thermostat sensor also checked magnetron
Photos / video link:

[DavidP_APP_Team]

Your mag tube is shorted out more than likely. Remove the mag tube and look inside the hole to see if the wave guide is burned If the wave guide, is burned, the MW will have to be replaced.

[TINO15150]

What is the Mag tube

[TINO15150]

[TINO15150]

will this be causing the issue

[DavidP_APP_Team]

Magnetron Tube, you have some pictures of it on your post.

[TINO15150]

Would these marks be causing the issue