White Rodgers Thermostat Screen is Blank even after changing batteries

[michael95448]

I'm came home tonight to discover the White Rodgers thermostat screen blank and no heat in our cold house. I apologize in advance for the lack of some detail but I son is sleeping in the room that accesses the attic and I'm trying to make some progress on this while he is asleep. The fan slider works but the heating slider doesn't. I checked the breaker box and there was one breaker tripped but I'm not entirely sure it was the FAU breaker. It could have been the breaker next to the FAU breaker. I probably should have made a better point to remember which one was tripped looking at it the first time. I went into the attic to check on the FAU after replacing the batteries in the thermostat with no result. The power to the unit was on. As described on the outside of the RUUD FAU unit for starting up the unit, I unplugged it for a few minutes and restarted it. Still no heat. I did take a look at the control board and noticed that there were three lights: PWR, a middle light and third one that said FLAME or PILOT. The first two were lit but the third one was not. I have removed the air return filter. No improvement. Any idea what could be going wrong? I've heard the control boards can go out. If so, maybe I should just have an HVAC repairman come out? Any help is appreciated. I'd get a new control board myself but I wonder if the delivery time might be longer for me than a repairman who might have some in stock. There is also my lack of familiarity with the installation.