Hello all!
I did something very silly a few weeks ago, accidentally powered on the unit while I was rebuilding the head of my dual CTC printer. The heating element wires shorted briefly on the assembly.
The only casualty (as far as I can tell) was the MAX6675 thermocouple responsible for the left head, it was reporting the max temperature to the firmware and my board would shut down after a few seconds. As a temporary repair I removed the chip hoping the board would function with no input. Success I am able to print with one head again.
I have now soldered on another MAX6675, I have verified all the connections as being good. But the board still seems to think the head is at 0 degrees constantly (i.e not getting a signal from the thermocouple). Now seeing as before I removed the bad chip, the max temperature was being reported I think it is unlikely that another component has been blown.
Could anyone give me ideas for what I can check/test? I really would like to be able to print with two filaments again.
Thanks for your help 
Try wiring the right extruder thermocouple to the left extruder input in the board and Vice-versa for the left to make sure the thermocouples are okay.
