Fault Phenomenon: XCMG XR280 rotary drilling rig operating the handle, instrument no response, actions fail.

Troubleshooting Process:
– Checked sensor: internal handle potentiometer worn open circuit.
– Checked harness: harness worn, short to ground.
– Checked connector: connector water ingress, oxidation.
– Checked power supply: 24V supply missing.

Root Cause: The internal potentiometer of the electronic handle is worn and open circuit, preventing signal transmission.

Required Parts: Replace electronic handle assembly.