Blog - Martronic

Fanuc Power Supply Repair

CNC drives and controls are probably one of our largest category of repairs seen.

A customer with a large 5 axis CNC machine had a breakdown on their Fanuc machine, with the power supply reporting a fan alarm. 

We removed the power supply and brought it back to the workshop where it was apparent the unit was extremely contaminated from the surrounding environment.


We dismantled the power supply completely into its component parts. The heatsinks and casings received ultrasonic cleaning and degreasing in our heated cleaner. The PCB's were cleaned using aqueous cleaner, which then revealed corrosion damage to some tracks. We also found the cooling fan had completely failed.

We remade the corroded tracks using repair wire, followed by green overcoat for protection. All capacitors were replaced, and a new 3 wire cooling fan was fitted. This is a special fan which incorporates a signal to inform the drive if the rotor fails to turn.

Once rebuilt we powered up the unit, all alarms cleared.

Another successful repair, with a customer so happy he is sending in the drives in the near future for preventative maintenance servicing.

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