I had a thermostat get hot and smell, replaced thermostat. Still not working found fuse on control board blown replaced fuse. Lights on control board indicate no problems. Replaced 18/5 cable from control board to thermostat. Still not working. Replaced cable from control board to condenser. Was able to manually start compressor and fan on condensing unit. But still not turning on. Did jumper tests from R thermostat lead and fan and R to A/C wire on control board, both caused 3amp fuse to blow on control board. Replaced 24v transformer was getting high voltage. Still not working. I don't know what to try next, I would think a control board but the heat works and the lights say it is operating fine. This is a Lenox brand system. Please advise.