HP Z8 G4 Maintenance And Service Manual page 60

Poor performance.
Cause
Hard drive fragmented.
Program previously accessed did not release reserved memory
back to the system.
Virus resident on the hard drive.
Too many applications running.
Some software applications, especially games, are stressful on
the graphics subsystem.
Cause unknown.
Computer powered off automatically and the Power LED flashes red four times and then white two times.
Cause
Processor thermal protection activated:
A fan may be blocked or not turning.
OR
The heat sink is not properly attached to the processor.
System does not power on and the LEDs on the front of the computer are not flashing.
Cause
System unable to power on.
52 Chapter 6 Troubleshooting without diagnostics
Solution
Defragment hard drive.
Restart the computer.
Run virus protection program.
1. Close unnecessary applications to free up memory.
2. Add more memory.
3. Some applications run in the background and can be closed by
right-clicking on their corresponding icons in the task tray. To
prevent these applications from launching at startup:
a. Type msconfig in the taskbar search box, and then
select msconfig.
b. On the Startup tab of the System Configuration Utility,
click Open Task Manager.
c. Select applications that you do not want to launch
automatically, and the click Disable.
1. Lower the display resolution for the current application or
consult the documentation that came with the application for
suggestions on how to improve performance by adjusting
parameters in the application.
2. Add more memory.
3. Upgrade the graphics solution.
Restart the computer.
Solution
1. Ensure that the computer air vents are not blocked and
the processor cooling fan is running.
2. Open the access panel, press the power button, and see if
the processor fan (or other rear fan) spins. If the fan does not
spin, make sure the fan cable is plugged onto the system
board header.
3. If a fan is connected and not operating, replace it.
Solution
Press and hold the power button for less than 4 seconds. If the hard
drive LED turns white, then:
Press and hold the power button for less than 4 seconds. If the hard
drive LED does not turn on white then:
1. Check that the unit is plugged into a working AC outlet.