Check the main electrical connection in the range junction box first. It may have come loose and this repair may correct all issues at once. If the main connection is good then access the monitor panel wiring by lifting the end, (I want to say the left) very slightly and sliding the whole black panel to the right to release it from the hood. once you have it loose, pull it out enough to access the wiring for troubleshooting. These systems are 12 vdc and I suspect you are correct in that there is no power getting to them; at either the main connection or behind the panel.
Mike, RVIA & RVSA Certified Master RV Technician
Amy, Dr. Assistant - Roxie & Mei Ling, four legs each
2000 Gulf Stream Scenic Cruiser 450 hp & 1330# torque
06 Saturn Vue, 06 Chevy Z71 4x4 & 2014 Corvette Z51 M7