I had been away for a week or so, and my iMac was sitting there with no use during that week. There might have been a few short power outages from the snow storms that have been crushing the north east, but other than that nothing has happened. Went to go do some work on the iMac this morning and my usb keyboard isn't working. I checked to make sure it's plugged in, and I changed the usb ports that it was plugged into, but nothing seems to fix the problem. Wondering if anyone else has experienced this issue and how to solve it? Any input would be great, thanks!