Check the spark gap.. On mine it was a bit..er.. Wide..
One of the problems with both Atwood and Suburban is the single wire infighter flame sensor system NOTE I do not think this is your problem because when this happens it LIGHTS but shuts off you said it does not light.
IF the change over from SPARK to "Sense flame" goes wonkey.. the "Sense flame" chip which is looking for a fraction of a volt DC on the wire gets hit with about a kilovolt (1000volts) AC or about 1400 volts DC and.. Pop goes the sensor.
I had that happen (At least I think that's what happened) Ordered a replacement control board from Dinosaur boards...
First impresion (I'm trained in electronics) when I opened the box was QUALITY and upon a closer inspection right next to where I think such a sensor chip might be is a handy dandy protection device (Gas discharge tube, a kind of spike or surge supressor) Seems Dino boards thinks same as I do.