Samsung OTR Microwave - Turns On, No Heat

Hey all thought I'd get some insight before I put more money into this unit.

I have a Samsung ME18H704SFS over-the-range microwave that worked fine until last week when turning it on to heat something up I heard a pop and a slightly different noise/hum than usual. Afterwards nothing has heated up but all other functions of the microwave work.

Initially I found one of the bottom thermal fuses blew, makes sense because before using the microwave I had a pot boiling for 2-3 hours and stupid me didn't turn on the exhaust fan. Yet replacing the fuse didn't change anything.

So far all fuses/door switches test good as well as the capacitor. I did find that the high voltage diode blew but everything else such as the magnetron and transformer test okay. Interestingly enough after replacing the thermal fuse whenever I plug it in the microwave the exhaust fan immediately kicks on and it does not respond to the on/off button on the panel. The panel worked fine prior to the heat issue. Only a handful of times plugging and unplugging it has the fan not turned on. This is leading me to wonder if the controller board is toast too or if the diode is the only culprit here.