Hi, I saved this keyboard from the reciclyng yard since someone in my office has thrown it away. The reason is the keyboard is not recognized by any computer when plugged in the USB port. Even the led on the caps key won't turn on. I tried to open it in order to see if the USB cable was damaged but everything looks in order (I tested with a multimeter). Am I completely hopeless or is there something I could check in order to try a repair?