771 Error

Try swapping this "bad" Receiver with one of your good Receivers.  If the problem stays with the "bad" Receiver, you can be pretty sure it's defective.  If the problem stays in its room, then something is wrong with the TV in that room.  Let us know what you find.

Would it happen to be that the ones with the 771 error are high definition receivers and the ones that are OK are standard definition?  The high definition channels are more susceptible to a misaligned antenna as well as a few other faults.  By the way, just to be clear, SL5 is a dish type, not a receiver type.  The receivers are your set top boxes.

Best to start your own new thread using the "Create New Post" button on the main forum page.  Your problem may very well be different from the original poster's.    With a new thread you can provide more information about your equipment, location, and troubleshooting you've tried so far.  And this forum software makes it difficult to track or respond to folks that add onto someone else's thread. 

99% of these problems are caused by dish misalignment.  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 (16 total at 99º(s)) [or 99º(b)]

[Local HD channels for some cities]

1-8    #   #   #   #   #   #   NA  NA

9-16   NA  NA  NA  NA  NA  NA  #   #

17-24  #   #   #   #   #   #   #   #

[Note: these can be very slow to appear]

Satellite transponders (14 total at 99º(c)) [or 99º(a)]

[National HD channels]

1-8    #   #   #   #   #   #   #   #

9-16   #   #   #   #   #   #   NA  NA

[Note, these can be very slow to appear]

Satellite transponders (16 total at 103º(s)) [or 103º(a)]

[Local HD channels for some cities]

1-8    #   #   #   #   #   #   NA  NA

9-16   NA  NA  NA  NA  NA  NA  #   #

17-24  #   #   #   #   #   #   #   #

[Note, these can be very slow to appear]

Satellite transponders (16 total at 103º(ca))

[National HD channels beamed from D12 satellite]

1-8    NA  NA  NA  NA  NA  NA  NA  NA

9-16   #   #   #   #   #   #   #   #

17-24  #   #   #   #   #   #   #   #

Satellite transponders (14 total at 103º(cb)) [or 103º(b)]

[National HD channels beamed from D10 satellite]

1-8    #   #   #   #   #   #   #   #

9-16   #   #   #   #   #   #   NA  NA

17-24  NA  NA  NA  NA  NA  NA  NA  NA

Satellite transponders (9 total at SWM)

[You'll only see this if you have a Single Wire Multiswitch (SWM) dish]

1-8    #   #   #   #   #   #   #   #

9-16   #   NA  NA  NA  NA  NA  NA  NA

Both tvs that are not working have HD receivers.

Satellite transponders (32 total at 101º)

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

1-8    76 74 55 71 91 73 92

9-16  72 77 77 68 76 95 74 95

17-24  72 94 77 67 77 95 8 95

25-32  73 97 72 72 75 95 73 95

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  85

9-16   NA  91   NA  88   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  96  0  96  

25-32  98  97  97  97  96  98  74  98

Satellite transponders (16 total at 99º(s)) [or 99º(b)]

[Local HD channels for some cities]

1-8    0  0  0  0  0  0  NA  NA

9-16   NA  NA  NA  NA  NA  NA  0  0

17-24  0  0  0  0  0  0  0  0

[Note: these can be very slow to appear]

Satellite transponders (14 total at 99º(c)) [or 99º(a)]

[National HD channels]

1-8   0  0  0  0  0  0  0  0 

9-16  0  0  0  0  0  0   NA  NA

[Note, these can be very slow to appear]

Satellite transponders (16 total at 103º(s)) [or 103º(a)]

[Local HD channels for some cities]

1-8    0  48  46  0  0  0   NA  NA

9-16   NA  NA  NA  NA  NA  NA  0  68

17-24  0  61  0  68  0  0  0  0

[Note, these can be very slow to appear]

Satellite transponders (16 total at 103º(ca))

[National HD channels beamed from D12 satellite]

1-8    NA  NA  NA  NA  NA  NA  NA  NA

9-16  43  54  41  51  41  51  33  50

17-24  36  50  35  47  35  51  32  47

Satellite transponders (14 total at 103º(cb)) [or 103º(b)]

[National HD channels beamed from D10 satellite]

1-8    26  54  29  56  31  57  32  59

9-16   32  58  32  60  30  58   NA  NA

17-24  NA  NA  NA  NA  NA  NA  NA  NA

Satellite transponders (9 total at SWM)

[You'll only see this if you have a Single Wire Multiswitch (SWM) dish]

1-8    95    98  95  95  98  99  73  73

9-16   73   NA  NA  NA  NA  NA  NA  NA

Your dish has apparently moved or has some other problem. (it isn't covered with snow is it?) You'll need to get a tech from Directv out to re align it. The signals you have are so bad that I'm surprised you get any HD channels at all. The visit is free with the Protection Plan, otherwise $50.

It could be covered with leaves...I will have to get up there and take a look. I am wondering why our other two tvs work fine, though. Thanks!

SD signals have flat wide tops and are very forgiving when off center.  HD signals are narrow and sharp topped and must be spot on to work.