I had the same problem. After weeks of reading and troubleshooting, I ended up replacing my junk Suburban ignition control board with a Dinosaur Electronics UIB64 Ignition Board. Works for Suburban and Atwood. I set the jumpers on the board based on the instructions and plugged the power back in. Everything has been better than new ever since. Even has LED lights to indicate the board's status. I'm not an electrician but it was actually pretty easy.
