Fault Phenomenon: Cormach truck crane operating the electro-hydraulic proportional handle, the corresponding action does not respond, and a multimeter shows no current output.

Troubleshooting Process:
– Checked handle power supply: normal.
– Checked CAN communication: normal.
– Checked internal handle circuit board: circuit board damp and corroded.
– Drying was ineffective; replaced handle assembly.

Root Cause: The internal circuit board of the proportional handle was damp and corroded.

Required Parts: Electro-hydraulic proportional handle assembly.