Solving power supply problems
This section presents power supply troubleshooting scenarios.
Testing power supply
Before replacing the power supply, use the Built-In Self-Test (BIST) feature to learn if the power supply
To test the power supply:
Disconnect the AC power.
Remove the internal power supply cables from the system board. (You do not need to remove the
power supply from the chassis.)
If necessary, disconnect the PCIe power cable from the graphics card.
Plug in AC power and verify the following:
See the Rear panel components section of this service guide to locate the BIST LED on this workstation.
Power supply shuts down
Workstation powers off and the
Power LED flashes red 2 times
(once every second), followed by a
Power LED flashes red (once every
148 Chapter 6 Diagnostics and troubleshooting
If the green BIST LED on the rear of the workstation is illuminated and the fan is spinning, the
power supply is functional.
If the green BIST LED is not illuminated or the fan is not spinning, replace the power supply.
Power supply problems
Power supply fault.
Processor thermal protection
A fan might be blocked or not
The processor heatsink fan
assembly is not properly
attached to the processor.
Power failure (power supply is
Replace the power supply.
Ensure that the workstation air vents are not blocked.
Open the access panel and press the workstation
Verify that the system fan is running.
Verify that the processor heatsink fan spins.
If the heatsink fan is not spinning, verify that the fan
cable is plugged into the system board connector.
Verify that the fan is properly seated.
Replace the processor heatsink.
Determine whether a device is causing the problem
by performing the following:
Disconnect AC power.
Remove all attached devices.
If necessary, disconnect the PCIe power cable
from the graphics card.
Power on the workstation.
If the system enters the POST, perform the following:
Power off the workstation.
Replace one device at a time and repeat this
procedure until a failure occurs.