Temperature sensing issue but thermocouple ok

I have the old "Tool 1 Failure. Temperature limit reached" problem on my Creator Pro. The temperature reading on the left extruder is NA while the right reads the correct temperature. I've checked the thermocouple and it seems to be ok - swapping the left and right sensors around gives the same results.

The problem started when I removed the left extruder nozzle to clear out a blockage. In the process of removing it the heater block twisted a little.

Could have this caused some damage? I'm worried that the mightyboard may be fried!

Thanks