Solving Power Supply Problems; Testing Power Supply - HP xw6400 Service And Technical Reference Manual

Table 5-3 Minor problems (continued)
Problem

Solving power supply problems

Testing power supply

Before replacing the power supply, use the Built-In Self-Test (BIST) feature to learn if the power supply
still works.
To test the power supply:
1. Unplug the AC power.
2. Disconnect all internal power supply cables from the system board.
3. Plug in AC power.
●
If the green BIST LED (illustrated below) on the rear of the workstation is illuminated and the
fan is spinning, the power supply is functional.
●
If the green BIST LED (illustrated below) is not illuminated or the fan is not spinning, replace
the power supply.
112 Chapter 5 System diagnostics and troubleshooting
Cause Possible Solution
Press and hold the power button for less than 4 seconds. If
HDD LED does not illuminate, then:
1. Verify that the unit is plugged into a working AC outlet.
2. Open the access panel and verify that the power button
harness is properly connected to the inline front panel
I/O device assembly connector.
3. Verify that the power supply cables are properly
connected to the system board.
4. Verify the power supply functionality.
a. Disconnect AC power.
b. Remove all internal power supply cables from the
system board.
c. Plug in AC power.
● If the power supply fan spins and the BIST
LED illuminates, then the power supply is
good. Replace the system board.
●
If the power supply fan does not spin or the
BIST LED does not illuminate, replace the
power supply.
ENWW