Siemens S5-155U System Manual page 110

Power Supply Units
Other faults
4 - 40
Other faults can be indicated by the green LEDs on the front plate
going off.
Indication Possible Cause
Green LEDs go The Enable jumper is
off and the out of place
power supply
fails. Latching
Off-switching by
overvoltage at output
Internal fault in the
PSU
Action
Check the jumper.
Switch the supply voltage
off and on again. If this
does not clear the fault,
there is an internal fault.
Send in the PSU for repair.
System Manual
C79000-B8576-C199-03