Only one PSU has a communication fail.

1. Check if the PSU is correctly inserted in the PSU power rack.

2. Check power cables between PSU and power rail in the mains input compartment (reference 1 image and reference 2 image)

3. Check if the PSU is powered. Ensure that the three phases of the mains power is correctly wired.

Multiple PSU have a communication fail.

1. Check if the communication wire between the PSU power rack (RJ45 plug, reference 5 image) and Laser Control board (10 pole connector, reference 6 image) is properly inserted.

2. Check if the communication wire between the PSU power racks is properly inserted (reference 3 and 4 image). (only applicable in case two power racks are installed).