Performed AC diagnostic on 2001 comfort maker thermostat. Pierre Stated that he had just tried to swap the thermostat out this morning because the old one wouldn’t work. After new thermostat was installed indoor blower motor would not turn on. I started by checking for voltage at the thermostat and found a 27 V was present, I then jumped out R and G to turn the fan on and there was no response from the system. I proceeded to the attic and found that the system did have power present and the 5 AMP fuse was intact. Directly jumped out the board And there is still no response for the motor to turn on. Bypassed the motor directly into the in-line door switch and motor turned on. This indicates to me that the circuitboard is gone bad and is no longer functioning for the indoor blower motor. There’s also signs of burn marks On the circuitry of the board. Pierre Is selling the house and it is in escrow right now. He said he’s going to do his research on the board and give me a call tomo