Tadiran Telecom Coral IPx 800 Series Installation Procedure And Hardware Reference Manual page 347

6 Troubleshooting (PS19 DC-D)
Power supply failure generally results in the loss of one or more output voltages.
However, protection circuitry in the power supply regulator circuitry may shut down
a regulator because of a current overload caused by an external fault.
The red Alarm indicator on the front panel of the PS19 DC-D lights when any of the
output voltages are outside of specification. This may be caused by internal or external
faults. The technician must isolate the problem and replace the faulty unit when
necessary, see below.
The red Alarm indicator illuminates if any voltage supplied by the power
supply is outside of specification. This could be caused by an internal or
external fault. If the alarm indicator illuminates in a replaced power supply,
the fault is not within the unit.
All maintenance activities are to be carried out by a qualified service technician.
The red Alarm indicator can be activated by malfunctions in the backplane, the power
supply, in any of the cards inserted into the cage, or in any of the above in a connected
cage.
For Redundant Peripheral Power Supply Units
(i.e. one PS19 DC-D installed on each of two adjacent shelves and connected via a
cable on the backplane, see
If one of the units is faulty, while the second unit is functioning properly, then
the "red (ALARM) lit" unit is at fault and should be replaced.
If both units have the red ALARM indicator lit, then both shelves are not
functioning properly and the problem must be isolated to either both the units
or one of the peripheral shelf cards.
Alternatively, the PS19 DC-D unit may not light any Power or Alarm indicator and
shut down. Following the shutdown of a P19 DC-D unit, the F1 fuse within the
PS19 DC-D or the fuse on the rear panel cage should be replaced. If this does not
restore the unit, then the unit should be replaced.
):
Figure 7-8
7-33
Power Supplies