UPDATE - Dometic #RM2652/2852 "Check" lignt blinking

To work your refer requires 12VDC and either 120VAC or propane. Turn the propane on at the tanks, turn on stove burners until you get a good solid flame. If propane has been off there can be air inmthe lines. You need to purge the gas lines first.
If you have strong 12VDC, then attempt to start the refer. It may still take several attempts to light it off. Once you know you have good 12VDC and 120VAC you can try switching to electric only. There is a fuse on the main panel that my have blown.