HP Z800 Maintenance And Service Manual page 238

Table 6-2
Problem
Workstation powers off and the
Power LED flashes red 2 times
(once every second), followed by a
2-second pause.
Power LED flashes red (once every
2 seconds).
226 Chapter 6 Diagnostics and troubleshooting
Power supply problems (continued)
Cause
Processor thermal protection is
activated.
A fan might be blocked or not
turning.
OR
The processor heatsink fan
assembly is not properly
attached to the processor.
Power failure (power supply is
overloaded).
Solution
1. Ensure that the workstation air vents are not blocked.
2. Open the access panel and press the workstation
power button.
3.
Verify that the system fan is running.
4. 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.
5.
Replace the processor heatsink.
1. Determine whether a device is causing the problem
by performing the following:
a. Disconnect AC power.
b. Remove all attached devices.
c. If necessary, disconnect the PCIe power cable
from the graphics card.
d. Power on the workstation.
If the system enters the POST, perform the following:
a. Power off the workstation.
b. Replace one device at a time and repeat this
procedure until a failure occurs.
c.
Replace the device causing the failure
d.
Continue adding devices one at a time to verify
that all devices are functioning.
2. Verify power supply functionality.
a. Disconnect AC power.
b. Remove the power supply.
c. If necessary, disconnect the PCIe power cable
from the graphics card.
d. Plug in AC power.
If the power supply fan spins and the LED
●
illuminates (see
on page 225), the power supply is good.
Replace the system board.
If the power supply fan does not spin or
●
the LED does not illuminate (see
power supply on page
power supply.
Testing power supply
Testing
225), replace the
ENWW