Solving Usb Problems - HP ProSignia 120 Maintenance And Service Manual

Table 2-26 Solving Screen Problems
Problem
Display on an external monitor
is distorted.
The image has a black border
and does not fill the screen.

Solving USB Problems

Problem
External device connected to a
USB connector does
not work.
External device connected to a
USB connector does not work
during startup (before
Windows 95 loads).
External devices in lower tiers
do not work.
2-32 Troubleshooting
Continued
Probable Cause
Incorrect display device
drivers are installed or
incorrect resolution is set.
The external monitor is not
Energy Star compliant, but
monitor energy saving feature
is enabled.
The Desktop Area setting is
smaller than the Resolution
setting.
Table 2-27
Solving USB Problems
Probable Cause
The operating system limits
external devices connected by
USB to two tiers that can
include no more than two
hubs on the first tier and no
more than one keyboard and
one pointing device on the first
or second tier.
During startup, only two tiers
are supported by the USB
connector. These tiers can
include no more than two
hubs on the first tier and no
more than one keyboard and
one pointing device on the first
or second tier.
An unpowered hub is
connected to another
unpowered hub.
Recommended Action(s)
Double-click the Display icon in Control
Panel, click the Settings tab, and set the
correct display type and resolution for the
external monitor.
Complete these steps:
1. Press any key or move the pointing
device to restore the display.
2. If display remains distorted, turn off the
monitor, then turn it on again.
3. Disable the monitor energy saving feature
in Display Properties or in Computer Setup
Power Management.
Adjust the settings for the Desktop Area and
Resolution. Double-click Control Panel
Display Settings Compaq.
Press the Fn+T keys to expand the image.
Recommended Action(s)
Reduce the number of connected external
USB devices to no more than two hubs on
the first tier, and no more than one keyboard
and one pointing device on the first or
second tier.
Use the external device only after Windows
95 has loaded.
Reduce the number of connected external
USB devices to no more than two hubs on
the first tier, and no more than one keyboard
and one pointing device on the first or
second tier.
Use only powered hubs.
Make sure that all unpowered hubs are
immediately preceded by powered hubs in
the USB chain.