I have a set of 20-20189-1 PS3 F-7’s an ABA set. I went to run them and noticed that the smoke fan motor unit was not working in the trailing A unit. I disassembled the smoke unit. The smoke works but the fan does not. I connected the fan motor to a power source to test it. It worked perfectly. I am by far not a train mechanic. I have very basic knowledge when it comes to this. Could there be something wrong with the circuit board that everything connects to? Any help is very much appreciated. Thank you and have a good day.