USB 2.0 Issues on IBM T40

There are many posts out there about USB 2.0 not working on IBM laptops. I did not find this particular issue anywhere, so here we go:

When I connected my USB 2.0 harddrive to my T40 it would always complain about a 2.0 device being connected to a 1.1 port. From then on all USB 2.0 devices would work like 1.1 (even my good ol' memory stick). I was able to re-establish 2.0 connectivity (for my memory stick, that is) by either

• removing all USB ports in Device Manager, then scan for hardware changes, or
• as so often with Windows, rebooting my computer

But as soon as I would connect my harddrive, the laptop ports were degraded again.

Finally I found the reason: apparently the harddrive, although being a 2.5" laptop drive, sucked up too much power. When I connected the harddrive to an external power supply, the ports would work fine in 2.0 mode. (I was lucky enough not to have damaged my mainboard, as some people had reported elsewhere)

Hope this may help some people facing the same issue.

P.S.: I am not saying this is the only possible reason for this behaviour, as the many forums on the internet show plenty of other causes. So if this does not solve your issue, do check the forums too!