USB PROBLEM DEBUGGING
15. March 2011


There are many reasons why an USB device might not work. Here is a list in no particular order, because I cannot guess which of these are relevant in your case and which are not:

1.
Not all USB devices work in all computers. Some new devices work in no computers. I just returned a WD disk which failed in 5 first computers that I tried.

2.
USB slots are not the same. Try another slot, in another location in your computer, it might work.

3.
USB slots are parallel (in some cases) in their power output. Try a slot which is not next to another device requiring high power.

4.
Extension cables will affect power output. Try without a cable or with a better/shorter cable.

5.
Certain USB devices work without an extra power input. However, it is also possible to attach external power input
in some cases with another cable or with double USB cable. Try that.

6.
If your USB device (like a network USB device) has as an extra feature something like a memory chip (SD card), that will affect power requirements. Try without the chip installed.

7.
Are you running latest BIOS? USB problems typically need a BIOS fix.

8.
Are you running latest drivers? Search Dell (or other vendor) support for the latest drivers. (This is typically a Windows-only problem).

9.
It is possible that OS is to blame and reinstall would be required. However, this is the least likely reason and can be ruled out with the next item. (This is typically a Windows-only problem).

10.
You can check your hardware and OS for faults - boot from a Live Linux CD and try the device there. Puppy Linux is especially handy for this. Also Ubuntu Linux is good but slower to start. If they do not work in your particular computer, try some other Linux distro, there are many of them. If not obvious, booting from a Live Linux CD, does nothing for your hard disk. You can also use an USB stick for booting up, but that might be slightly more difficult to master - and also perhaps not that good an idea in this case when you are testing how USB works with your hard disk.


Windows related only:

1. If you have a software that cleans the registry, use it, reboot and try to plug in the device again. However, please observe that some registry cleaners remove some application software from your computer as well and thus your applications might not work after you run it. So you can only use a registry cleaner that you are familiar with.


2. Try to uninstall and reinstall the driver. Sometimes this happens because the driver for the particular device has already been installed but has missing components.