usb device not recognized

Hello, I've got a SGS2 (i9100) from a collegue to repair. It doesn't boot, only the "Samsung GALAXY S II GT-I9100" screen appears. It has probably Jelly Bean 4.1 software. I can get into download mode, but can't open recovery mode. In download mode the text on screen is: ODIN MODE PRODUCT NAME...

I have problem with my nexus, This error shows up few days ago when i tried to plug my phone to computer. So i can't transfer data, and what is more i can't change rom to stock 4.4.3. And now what I've tried to do. - I checked a few cables - on other computers - tried to use fastboot on linux...

When I tired connecting my HTC vivid to my computer through the recovery's 'enable MS-USB' option, my computer (Windows 7 64-bit) states that is does not recognize the device (I get the list of ports, and can see the "unkown device"). I've plugged it in multiple times, but it still doesn't...

Ok, I just plugged my phone into a front USB port on my computer I havent used in forever. My PC locked up, and I had to reboot. So taking it as a bad sign, I plugged the phone into the rear port as usual, and now I get a message saying that the device I plugged in has malfunctioned, and windows...