I looked up the #1 reason for no heat for my microwave on the site , and using my model number found that 92% of the time it was the Black Sleeve Diode. Ordered the $15 part, and installed it within 30 minutes. Most of the time was used for removing the built in microwave and removing the cover. Replaced the diode by finding it on the diagram that I printed from this site (free). Very relieved that we don't need to have our custom cabinetry re-sized to accommodate a new microwave. Thank you!
Removed case, Discharged HV capacitor and removed cooling fan. Unscrewed ground end of HV diode and unplugged from HV capacitor. Installed new diode by reversing the order. In my case, the problem was the magnetron was bad, so I replaced it as well.