KNK Zing Head Cable
Zing blade lifts (especially on left part of Zing)
Dry joint at head cable
With power off, gently move the carriage to the left side, but not touching the limit button.
Press and hold the left limit, turn on power, and when the carriage stops at the right, immediately release the left limit.
Within a few seconds the cutter will start a continuous loop self test, which is helpful to see if we have bad head cables, motor action, laser power, etc.
While it is not a finite conclusive test, it can help to see what functions are there.