I believe I shorted something out as I was changing over from a basic digital thermostat to a 7 day digital thermostat. As I was pulling the old mount off the elec. tape slipped off the blue (common) wire and sparked. I re-wrapped the line and continued with my installation. When I put the new thermostat (Hunter) on I got an error msg that said there was no a/c power (it was using battery power). I put the old thermostat back in and the display screen is blank. I checked the 2 other thermostats and they also had blank screens. I did a little research on the internet (love google) and my guess is that I must have shorted out the transistor or blew a fuse. I checked all the breakers (reset each one) and then reset all the gfci outlets (thinking that maybe they were somehow tied together). I went into the attic and reset the breaker for the air handler and I still have no power to the thermostats. I looked around the air handler in the attic and didn't see an access panel (I'm not used to electric heat - I knew how to check the gas furnace at my old house) to look to see if the "purple" fuse was blown. Any suggestions?