I got an HR21 last week & it seemed to reconzize my external drive for a little while. The next day the box all of a sudden reset itself & now it doesnt seem to reconize the external drive. I tried several methods to get it to work again but they have failed. Another thing is when I took out the eSata cable from the hard drive, the hard drive turned off although the power cable was still plugged in. It acts as if the DVR gives it its power when the drive has it's own power supply. I reset the dvr several times, then the ultimate reset which was unplug the DVR. Any suggestions would be appreciated.

Try the HR20/21 section at dbstalk.com, it's the best resource for these models.