I recently acquired a brand new DZ77BH-55K motherboard currently running with the latest bios update (BHZ7710H.86A.0096.2012.1219.0921). It's powered by a high quality 650W Seasonic power supply, which is more than enough to run smoothly everything I have in my system.
The problem I've been encountering right from the start (at least ever since I did my first bios update few days after its setup) is that absolutely no USB port (either rear or front, USB3 or USB2) is able to make any of my USB2 peripherals work, while any USB1 peripheral (mouse, keyboard, several midi controllers, etc...) works perfectly. I didn't care much at the beginning since I only had an old 1 Gb flashdrive that could have been using USB2, but I recently acquired a quite expensive external soundcard which also happens to use USB2 and this made me realize that the problem seems much more serious than I thought (not just like the usual stuff that happens all the time with Windows and unrecognized flashdrives).
Even worse, the behavior of plugged USB2 devices is sometimes quite weird and scaring. Most of the time the device just seem to be stuck in a power ignition loop. The light from my USB stick keeps flashing eternally and my soundcard does pretty much the same (which is really not very reassuring considering its price). If you're lucky, sometimes it quickly stops and Windows pops an "Unrecognized Device" error up. I think this has a lot more chances to happen when you try this with a USB3 port.
Obviously, there's absolutely nothing wrong with these devices, as they're working perfectly on my laptop right off the bat. At first, I really thought it was something to do within Windows 7, so I did quite some struggling related to unrecognized USB devices, but after giving up and doing a fresh Windows 7 install, the problem was still there. So, while I was at it, I booted up a fresh Live-CD of Linux (puppy linux distribution) to be really sure. Plugged a USB1 flashdrive. Worked in any port. Tried with my USB2 flashdrive. Didn't work anywhere... So I am now quite sure that my USB ports are completely broken!
I also tried to fiddle with some settings in the bios (disabled legacy mode for USB, disabled most ports, etc...), disconnected front panel USB cables, removed all my PCI hardware, apart from my GTX 560 graphic card, etc... Everything with no luck.
So there you have it. I seriously hope someone will be able to help me, because I pretty much tried everything that I could do!
Thanks in advance,
Edit 1 : Oh yeah, Just in case, I also tried many time to unplug fully my computer and let it rest.
PS : here's more details about my setup.
====== Board ======
Manufacturer Intel Corporation
Product Name DZ77BH-55K
Serial Number BQBH220000UU
BIOS Version BHZ7710H.86A.0096.2012.1219.0921
BIOS ROM Size 8192 KB
BIOS Release Date 19/12/2012
====== Processor ======
Manufacturer Intel(R) Corporation
Processor Name Intel(R) Core(TM) i5-3450 CPU @ 3,10GHz
Processor Speed 3,1 GHz
Form Factor Socket LGA1155
Hyper-Threading Technology Status Disabled/Unsupported