System information

17-24 Troubleshooting
COMPAQ CONFIDENTIAL - NEED TO KNOW REQUIRED
Writer: Karen Williams Saved by: JAbercrombie Saved date: 05/24/99 1:53 PM
Part Number: 103542-001 File name: Ch17.doc
Solving USB Problems
Solving USB Problems
Problem Possible Cause Solution
External device
connected to the
USB connector
does not work.
The computer is
running
Windows NT 4.0.
When the computer is
running Windows NT 4.0,
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.
External device
connected to the
USB connector
does not work
during
startup (before
Windows 95 or
Windows 98 loads).
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.
Use the external device only
after Windows 95 or
Windows 98 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.
A New Hardware
Found message
displays although
the external device
was previously
recognized.
The device was
previously
connected to a
USB connector on
a docking base.
No action is required.
Connect the external device to
the same USB connector each
time.
External devices in
the sixth tier do not
work.
Windows 95 and
Windows 98
support up to five
tiers.
Replace some hubs in the
first five tiers with hubs
containing additional sockets,
then connect the devices in
the sixth tier to the new hubs.
Connect some external USB
devices to other connectors.
External devices in
lower tiers do
not work.
An unpowered hub
is connected
to another
unpowered hub.
Use only powered hubs.
Make sure that all unpowered
hubs are preceded by powered
hubs in the USB chain.