HOWTO: USB stops working

[lisati]

One topic that crops up from time to time in these forums is what to do if devices connected by USB stop working when the computer has been turned on for a while, but come right when the computer is rebooted.

The following solotuion is what I used when my USB mouse and USB keyboard worked fine at startup but stopped working after a while. I have successfully used it on a Toshiba A100 laptop running Ubuntu 7.04, a.k.a. "Feisty".

Disclaimer: The success (or otherwise) of the following solution will depend on your hardware and possibly which version of *buntu you are using. For example, starting from version 9.10, Ubuntu uses grub2, which does not use menu.lst
Feel free to add your feedback to this thread and alternative solutions.

1. From a terminal, type

   gksudo gedit /boot/grub/menu.lst

   You will be asked for your password - don't worry if your password doesn't show, this is normal. Just type in your password as usual, and it will be accepted.
2. When the editor opens, scroll down to the line which reads

   # defoptions=quiet splash

   and change it to read

   # defoptions=quiet splash acpi=force irqpoll

3. Save the file, exit the editor
4. From the terminal, type in

   sudo update-grub

5. Restart your computer.