Atwood uses 12V DC to power electric (via relay) and propane.
So check for blown DC fuse in Dist. Panel
Check the fuse on circuit board.
Pull connector on circuit board and clean contact surface with pencil eraser.
When electric ON/OFF switch is ON
Should be 12V DC on WHITE wire in connector going to board
When propane ON/OFF switch is ON
Should be 12V DC on ORANGE wire in connector going to board
Then 12V DC coming out of board on BROWN wire going to thermal cutout then thru normal t-stat terminals
Find out where 12V DC is lost
If you have it going to board but not out brown wire......bad board
Common components electric/propane
12V DC power
Circuit board
T-stats