I am having huge problems with my mightyboard.

Getting "Heating Failure #4" error.


I also noticed the board isn't reading any temperature at all from the extruders.

Makerbot support says to check the thermocouples. Did them one better and replaced both thermocouples. I was extra careful to connect the replacement thermocouples with the right polarity, so the leads are not reversed.

Didn't help, still getting "Heating Failure #4" error. Takes about 4 minutes to error out. The temperature readings for the extruders also still shows 000.

Well, both thermocouples (K type) for the extruders are read by the MAX6675 IC's, so I checked these as well I could.

I read the voltages for both MAX6675 IC's and they read the exact same. 5v at VCC pin#4 and 1.49v across VCC pin#4 to GND pin #1

Using Sailfish 7.5

It's hard to imagine both sets of thermocouples are bad and both sets of MAX6675 IC's are bad. Something else is going on and probably pretty simple.

Thanks!