I've got a '20 Magnitude SV34. You have two Coleman Mach 13,500 BTU A/C units. If they both work on generator power, there is no reason for them not to work on shore power unless you have an issue with the Transfer Switch or an issue from the 50A cord and wiring to the Transfer Switch.
If both A/C's are not working on shore power, check to make sure the microwave / convection oven actually is working on shore power. If not, then you need to start testing from 50A cable (plug it in and get your meter out and check that you have 120V on each leg). If power is getting through the cable, then you need to check to see if power is getting to the transfer switch and then out of the transfer switch on shore power.
Now if your fans run but the compressors won't start, it could be an issue with the FireFly System. The main G7 control board in the FireFly System needed replaced in my coach. I would have situations where the compressors would run and the fans would not. Or the fan would run and compressors would not. If I would power-cycle the 12V to reboot the system, it would start working properly but the same problems would happen again.
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