My Buffalo external hard drive is only a couple of months old, and no longer is being read by my computer. It doesn't show up in My Computer, device manager or anywhere else. When it turns on, it gives a series of 3 higher-pitched beeps, followed by 3 lower beeps, then 3 higher, then 2 lower. It didn't do that before, that I can recall. I've tried using it with another desktop computer - also doesn't work. Can you help?