The compressor fan motor went bad as did the capacitor and contactor set. Replaced all and after that, the fan for the air handler would not shut off even with A/C and heat off. One morning smelled an electrical fire, checked in the attic, the air handler and it appeared the fan motor for the air handler burned up. Replaced it and the capacitor and still nothing worked. Thermostat has no dispay, Further checking revealed the transformer burned and the circuit board had caught fire. Circuit board had an automotive type fuse in it, 15 amp which I understand should have been a 4 amp fuse. I need help in finding the circuit board and determining what may have caused this. Unit is oem to the house which was built in 1991 or 1992. Carrier unit with a number for the air handler of FB4ANF030.

Thanks in advance for any help on this. I am not an A/C guy but do have a friend who is and he has been helping me, but no luck on the circuit board and I want to find out why this may have happened.

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