My laptop (model "Dell Inspiron N5110") has four USB ports. Two of them work. Two of them don't.
The two ports that don't work have blue interior contact surfaces, instead of black/grey. A quick web search for "blue usb port" reveals that these might be USB 3.0 ports, and the other two USB 2.0. However, the method outlined here indicates I've only got 2.0, so colour me confused.
I've been trying various fixes for quite a while, without much success:
- Every setting in the BIOS that could possibly be enabled is enabled (except some anti-theft thing, but I don't think that's relevant).
- I've (re?)installed the "USB 3.0" drivers from Dell's downloads page. No dice.
- This answer suggests finding "Unknown Device"s in Device Manager and installing drivers for them. I don't have any unknown devices displayed, so I can't do that.
I would quite like to be able to use all four USB ports; troubleshooting assistance would be appreciated.
Best Answer
Here is a simple way to resolve the age-old question: Is it a Windows problem, or is it bad hardware? By testing the hardware with Linux, you will quickly be able to eliminate or verify the hardware as the root of the problem.
Boot your system with Linux on a USB flash drive; I prefer Puppy Linux for this, because it will run completely in RAM, saving you time and energy when diagnosing hardware problems. If the system won't boot with Puppy (not all systems will work with it), try booting with Ubuntu instead; I prefer 10.04.4 for hardware testing, because it uses Gnome instead of the vomit-inducing Unity interface.
If the USB ports work under Linux, you'll know that the hardware is good and the problem must lie within Windows itself. If the USB ports don't work under Linux at all, you'll know the controller chip for those ports must be defective.
If you don't know how to make a bootable USB flash drive with Linux, check out pendrivelinux dot com and learn some new skills.
Best of luck with this; hope this helps you.