Reference steps 1 and 2 to reassemble the bed heater power plug.

Leave the power cable unplugged to test the thermistor.

With everything hooked back up, you should be satisfied with your work!

After double checking that all wire connections are tight, it is a good time to test that both the thermistor work (in that order). You can plug in just the control box, display to test the thermistor.

If the thermistor is not plugged in (or broken), bed temperature will read -14.

If you have a normal ambient temperature reading on the display, you can plug the power cable in and test that the bed heats by going to manually setting the bed temperature to a low value of 50.