IBM 7378, Problem Determination And Service Manual

Page: 114 / 362

Power-supply LEDs
The following illustration shows the power-supply LEDs on the rear of the server.
Power cord
connector
AC power LED
DC power LED
Fault (error) LED
The following table describes the problems that are indicated by various
combinations of the power-supply LEDs and the power-on LED on the front
information panel and suggested actions to correct the detected problems.
Table 7. Power-supply LEDs
Power-supply LEDs
Description Action Notes AC DC Error
Off Off Off No AC power to
the server or a
problem with the
AC power source
1. Check the AC power to the server.
2. Make sure that the power cord is
connected to a functioning power
source.
3. Turn the server off and then turn the
server back on.
4. If the problem remains, replace the
power supply.
This is a normal
condition when no
AC power is
present.
Off Off On No AC power to
the server or a
problem with the
AC power source
and the power
supply had
detected an
internal problem
1. Replace the power supply.
2. Make sure that the power cord is
connected to a functioning power
source.
This happens only
when a second
power supply is
providing power to
the server.
Off On Off Faulty power
supply Replace the power supply.
Off On On Faulty power
supply Replace the power supply.
On Off Off Power supply not
fully seated,
faulty system
board, or faulty
power supply
1. If the system board error (fault) LED is
not lit, replace the power supply.
2. If the system board error (fault) LED is
lit, (Trained service technician only)
replace the system board.
Typically indicates
that a power supply
is not fully seated.
On Off or
Flashing
On Faulty power
supply Replace the power supply.
On On Off Normal operation
On On On Power supply is
faulty but still
operational Replace the power supply.
96
IBM System x3400 M3 Types 7378 and 7379: Problem Determination and Service Guide