Searching for Signal Error 771 only on local channels

Please post back with your signal readings for each satellite's transponders (and both tuners if applicable).  You'll find these readings under "Menu" -> "Setup" -> "System Setup" -> Satellite -> "View Signal Strength".  Note the "+" and "-" symbols next to the "Satellite" and "Tuner" entries where you can toggle the readings between the various satellites and both DVR tuners. 

Fill in your readings for each satellite and tuner using these examples.  A properly aligned dish will show 80-90s on most of the relevant transponders (although some will be low or zero):

Satellite transponders (32 total at 101º)

[Most of your standard definition channels are beamed from 101ºW]

1-8    #   #   #   #   #   #   #   #

9-16   #   #   #   #   #   #   #   #

17-24  #   #   #   #   #   #   #   #

25-32  #   #   #   #   #   #   #   #

Satellite transponders (3 total at 110º)

[Not present with Slimline3 dish. No channels are currently beamed from this satellite]

1-8    NA  NA  NA  NA  NA  NA  NA  #

9-16   NA  #   NA  #   NA  NA  NA  NA

Satellite transponders (11 total at 119º)

[Not present with Slimline 3 dish. Local SD channels for some cities, Spanish package]

17-24  NA  NA  NA  NA  NA  #   #   #

25-32  #   #   #   #   #   #   #   #

Satellite transponders (32 total at 101º A - Tuner 1)

1-8   93 92 92 100 92 95 94 96

9-16   93 93 94 99 94 96 93 96

17-24  92 99 92 99 93 96 93 96

25-32  93 95 92 94 94 96 93 97

Satellite transponders (32 total at 101º A - Tuner 2)

1-8   93 92 92 100 93 96 94 96

9-16   93 93 93 100 94 96 93 96

17-24  92 99 92 98 93 96 93 96

25-32  93 95 92 94 94 96 93 97

Satellite transponders (10 total at 119º B - Tuner 1)

1-8   NA NA NA NA NA NA NA NA

9-16   NA NA NA NA NA NA NA NA

17-24  NA NA NA NA NA 94 90 NA

25-32  96 96 95 94 96 96 65 97

Satellite transponders (10 total at 119º B - Tuner 2)

1-8   NA NA NA NA NA NA NA NA

9-16   NA NA NA NA NA NA NA NA

17-24  NA NA NA NA NA 94 89 NA

25-32  96 96 96 94 96 95 65 96

those readings look great. Where you getting the 771 error at the time?  If not, next time you see this error, please repost the signal readings.  You might have an intermittent connection somewhere. 

I did these readings right after I got the error and while the channels were not working.  Like I said in the post before, it is just the local channels.

Your local channels are beamed from the 119ºW satellite, and your signal readings look good there.  Not sure what else to suggest.  Do you have other Receivers/DVRs?  Are they working OK?

Might want to call DirecTV and request a service visit.  It's free if you have their Equipment Protection Plan, or within 90-days of installation. Otherwise ~$50.