Main power cable disconnected from the LPS unit (reference 1image "Mains and CTLB connection LPS").

Check if the main power cable is connected with the “MAINS INPUT” socket of the LPS unit.

Disconnected wire unit between the Signal Backplane and the LPS module (reference 2, LPS side and reference 3 Signal backplane side image "Mains and CTLB connection LPS").

Reconnect the wire unit between the Signal Backplane and the LPS module.

Malfunction of one of the LPS units. The red LED “ERR” of the malfunction LPS unit flashes fast.

Replace the whole LPS module. See "Lamp power supply" or "Lamp power supply (single module)".

Defect Signal Backplane.

Replace the Signal Backplane. See "Replacement of the signal back plane".