Microwave popped the breaker when I opened the door. Reset the breaker and it popped it again, then wouldn't work at all. Removed cover, found fuse blown. Replaced fuse, tried again, but it tripped the breaker again. Troubleshooting found bad 'monitor' interlock switch. After replacing that switch, it worked.
The door was a bit sticky, though, and the next day it popped breaker again. Checked fuse in microwave and it was still good, but interlock switch had same failure as before. Replaced again, re-aligned the door latch module better this time and everything works great. But no heat
. Checked all the interlock switches, and they seem to be working. Measured HV cap and it's within spec using DMM. Checked HV diode, and it looks good. Checked cavity and magnetron thermostats, and both are closed. Checked voltage at primary of HV transformer while pushing the cook button, and it starts to come up, but then I hear a relay click on the control board and no voltage. Any ideas?