Solving Usb Problems - Compaq Prosignia 150 User Manual

Problem
External device connected to a USB
connector does not work
External device connected to USB
connector does not work during
startup (before Windows 98 loads)
External devices in lower tiers do not
work
IMPORTANT: External USB keyboards will not function until the operating system has been booted .

Solving USB Problems

Possible Cause
The operating system limits external
devices connected by USB to two tiers,
which 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.
Solution
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 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.
Use only powered hubs.
Make sure that all unpowered hubs are
immediately preceded by powered
hubs in the USB chain.
User's Guide