Recently upgraded to the HR21-700. Ever since the upgrade we have experinced an error code 771 (searching for signal) on some of the HD channels. I did the reset thinking this might fix the problem. It did not. I was watching TV this morning and was getting this error on most of the channels, includeing the non HD. Did the reset and now receive an error of 771 (acquiring guide). Did the reset and still get the same 771. Contacted customer support and was walked through the process and still get 771. A tech is being sent out tomorrow. As of now we can not watch TV. Any suggestions? Device: HR21-700 only one unit in the house. Signal Strenght: Tuner 1. 57,54,51,0,51,60,0,55 Tuner 2. 57,52,49,0,50,57,0,54 Test Signal Strenght: Tuner 1. 56% Tuner 2. 56% If any other info is needed, let me know.