ununusual "usb ports not installing devices" issue

[burgerman]

have an e-machine el-1850 here (windows 7x64).. the problem is that it wont install any new USB devices such as powered or non powered external hdd's, usb wireless nics, usb wireless modems, and devices that were installed no longer function and need reinstalling

its same problem for both front and back usb ports on this machine (desktop)

it will however install a usb mouse and keyboard on any usb port.

1.) I had a fiddle with the OS (sfc tool and chkdsk) to check what might be done but decided to reformat the machine to its factory defaults.

2.) after a full wipe to factory defaults the problem still exists exactly as it was - mouse and keyboard usb functionality/installing is fine but any other type of USB device fails to install

3.) went into bios and set it to defaults - test and no improvement.

4.) then i updated the bios to the very latest version, reset to its defaults and there has been no improvement.

5.) i even check to make sure usb functionality was enabled in the bios and its on and seems fine.

6.) so i've gone and reformatted the machine again just in case a windows update did it or something. no improvement

7.) i've loaded up a dvd boot disk and tested the devices in that environment and there is no functionality in that environment either (although usb mouse and keyboard work)

I think its the motherboard thats faulty but im pretty stumped as to why the usb mouse and keyboard will work fine but no other usb device type will work (they all work fine in other machines).

what are your thoughts on this? im open to any suggestions or some theory as to what might be happening on the motherboard if it was to be this as fault. i hope this can be a learning experience for me (I've been fixing computers for 10 years as well).

as a computer tech do you think ive done a good enough series of fault checking tests without swapping hardware?- if not what else would you do ?

 

[NYJimbo]

Did you visually inspect all USB ports for any bent pins ? That's always the first thing I do when something is goofy with the USB stuff.

 

[burgerman]

i didnt do that but will next time. they look fine. and the silly mouse and keyboard works fine on all other ports.

other thing ive done is unplug all front usb connections to see it the back ones work.. no improvement

 

[cooltech]

What is the version of usb ports?

Have you boot up to live linux usb or cd dist? To test if usb works or not. That will also tell you if the hardware is bad or not.

 

[Aescaepulus]

Do the keyboard/mouse work on the "defective" ports? (nvm, actually read the full post!)

If so, then I'd lean towards reinstalling mobo system drivers, reset CMOS, get into BIOS and turn off USB control from BIOS (let OS configure USB ports). Lastly I'd do the RAM swap routine. If all fail, replace mobo (or if an eMachine under warranty, take it back).