Default [Q] Bad USB port

Just bought used atrix 2 on ebay, listed as for parts only. Problem was it wouldn't charge. Cleaned usb port with toothpick and alittle electrical contact cleaner. Port works sometimes for charging, but is not picked up by computer. I'm running a dual boot setup on computer, windows vista and ubuntu, and neither picks it up when plugged in with usb cable. Tried multiple cables and no luck. Call me dumb, but it will charge while hooked to computer, but nothing else, I don't get it. I'm assuming it's a hardware problem, is there a way to check this. Thanks for any help in advance. I'm off for more searching.