Issue:
Altivar Drive's display is blank

Product Line:
All Altivar drives

Environment:
Display doesn't light up

Cause:
n/a

Resolution:
Measure the input voltages (phase to phase) at L1, L2 and L3
Measure the DC bus at PA+ and PC-. DC voltage measurement should be ~1.41 times your line voltage.
Measure the +24v and +10v supplies. Measure to COM, not ground.
If the DC bus is ok, but the 24Vdc or 10Vdc is missing, then could be a problem with the Main Control board and/or the Power Board of the drive.