Performed diagnostic on 31 year old Carrier system. Homeowner states that his system is not cooling, indoor fan is turning on and off but condenser does keep running. He had an issue similar too this in 2017 and his buddy replaced the circuit board, told him that his unit was old but in good condition. I cycled system for cooling. Outdoor condenser kicks on normally, indoor fan motor goes on and off. Checked indoor unit electrical and system components. Found that thermostat is sending proper signal to board to turn fan on, but circuit board is not holding the command and turning fan on and off. Circuit board is once again bad and would need to be replaced. Indoor blower motor is also covered in oil and dust on back housing. This could be causing motor to run hot which in turn caused board to give out. Went over findings and recommendations with homeowner. He understands that the system is old however he wants to repair it and not replace it. Went over pricing on repairs, homeowner sta