# of USB Devices on IBM Laptop ?

[MWE]

This is probably an IBM laptop issue, but I have gotten
nowhere with IBM support, so I am trying other avenues ...

I have an IBM T40 laptop running WinXP. It is normally
docked in an IBM MiniDock. The T40 has two USB
connections; the MiniDock has four. If I have more than
two USB devices connected to the MiniDock when I power up
the laptop, the laptop will freeze at the first powerup
screen. This is all-too-common "complete freeze" where
nothing works including the on/off switch. The only way to
correct the situation is to undock, remove the battery,
replace the battery, redock and start again. Normally,
that process will then allow me to powerup successfully
with 3 USB devices attached. Not wanting to go through
this, I normally powerup with only the two most important
USB devices connected and then connect other devices when
needed (not often). This is a workaround that is
successful 95% of the time, but should not be required.
This is a relatively new laptop (1 month old). I have
talked with IBM several times about this. They claim no
knowledge of similar problems. I am running the correct
BIOS as of Aug'03. I have looked at the history of BIOS
upgrades; there have been some USB problem fixes. There is
a newer BIOS but it for T41 (newer model) functionality
and not (from what I can determine) for any bug fixes. IBM
suggests that I upgrade the BIOS but can not give me any
assurance that this will actually do anything. Any
thoughts?

Thanks

 

[Yves Leclerc]

This problem can exist with every USB equiped computer. Part of the USB
standard is that the USB ports are providing the required power to the
device. It could be that the laptop is not providing enough power to the
USB ports.

Have you tried a self-powered USB hub?

Y.