Carrier 30GB075 Flowtronic still with a Code 51

[thecomp]

I have a Carrier 30GB Flow-Tronic, which is still tripping on a Code 51 compressor failure.I jumped the HG and HP switch, and changed the cpcs board.

The only thing remaining according to the manual is current to ground, but the compressor is 3 months old and amping out OK. So, maybe I could dissconnect the toroid wires to the cpcs? But, Carrier says not to. I ran out of time and have to return.

I think the problem is the microprocessor board; it's the original from 1988.

[mfriar]

make sure the toroid is free around the wires and not stuck.sometimes this will so as a fault.if all else fails on your cpcs board is a com terminal a n/c terminal and a n/o terminal.only com and n/c have wires on them.put both of them on the com terminal

[joey791]

This is going to sound crazy but I saw it ONCE, on your microprocessor board there is a screw located pretty much in the center of your board, make sure that screw is there, it grounds the board to the unit and if it is missing it will do some wierd things.