HP ProDesk 400 G1 Maintenance And Service Manual page 75

Computer date and time display is incorrect.
Cause
NOTE: Connecting the computer to a live AC outlet prolongs the
life of the RTC battery.
Cursor will not move using the
Cause
The Num Lock key is turned on.
There is no sound or sound volume is too low.
Cause
System volume may be set low or muted.
Poor performance.
Cause
Processor is too hot.
Hard drive is full.
Low on memory.
Hard drive fragmented.
arrow keys on the keypad.
Solution
Replacement section for instructions on installing a new battery,
or contact an authorized dealer or reseller for RTC battery
replacement.
To access Control Panel in Windows 7, select Start, and then
select Control Panel.
To access Control Panel in Windows 8.1, from the Start screen,
type c, and then select Control Panel from the list of
applications.
Solution
Press the Num Lock key. The Num Lock light must be off if you
want to use the arrow keys on the keypad. You can also disable or
enable the Num Lock key in Computer Setup at Advanced >
Device Options.
Solution
1. Check the Computer Setup settings to make sure the
internal system speaker is not muted (this setting does not
affect the external speakers).
2. Make sure the external speakers are properly connected
and powered on and that the speakers' volume control is set
correctly.
3. Use the system volume control available in the operating
system to make sure the speakers are not muted or to
increase the volume.
Solution
1. Make sure airflow to the computer is not blocked. Leave a
10.2-cm (4-inch) clearance on all vented sides of the
computer and above the monitor to permit the required
airflow.
2. Make sure fans are connected and working properly (some
fans only operate when needed).
3. Make sure the processor heat sink is installed properly.
Transfer data from the hard drive to create more space on the
hard drive.
Add more memory.
Defragment hard drive.
Solving general problems 67