Error 82 problem. Tried multiple solutions.

Hello. My X-Box 360 S has had the E 82 error for a couple months. I have tried an AV and HDMI cable in it and the error stayed on display. The X-Box has no hard drive under the sliding plate on the side. It has a 16mb external drive plugged into the front that we have tried removing to fix the problem, but with no avail. Thanks.