[Burnin]

I'm no furnace expert, but if you are getting no response at all then it could be many things. The first thing that should happen when the tstat calls for heat is the exhaust motor should kick on. If this isn't kicking on, then I am suspect of the relay board that starts this motor. (The older bryants have clear plastic relay's and the newer boards are solid state relays).

To test this, you can directly power the exhaust motor by unplugging it from the board and rig up a direct 110volt connection to the motor. (make sure the tstat is calling for heat also when you do this) When the motor starts and creates vacume in the combustion chamber, the furnace should cycle correctly to a fire up.

If this works, it is likely the relay board that energizes this motor needs changed (not the main board). Now, I know this because this did happen to me a few years ago. But I also learned that the wiring to the new board was a little different than the old board. To make a long story short, I also had to swap out the harness before I had it fixed.

In any case, if you can direct power the exhaust motor and get the furnace to work, you're on the right track.