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New Member

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10 Messages

Thu, Nov 25, 2021 2:23 AM

771 loss of signal intermittent on SOME channels but not all... Bad LNB? Coax? example channel 355 Sat 103ba

All 4 of my receivers get a 771 loss of signal on a handful of channels including CNBCHD, MSNBCHD etc.. I'm wondering if I have a bad LNB and wondering if I can determine if the bad channels are all on one satellite and possibly the LNB or wht?. I see some maps that are old but the terminology doesn't match the receiver satellite receiver level check terminology. CNBCHD does it easily so I want to know which satellite and transponder its on so I can check its levels. One map I found online shows its on 103B with no transponder listed but the receiver has 103(s), 103(ca), 103(cb). I guessed 103(cb) = 103B and it appears to lose signal on the receiver level check on alternating odd transponders (1,3,5 ... 15) that come and go. That doesn't seem right but I don't know how odd/even transponders work or if there is something like a LNB control voltage that might be flaky or if this is normal and just looks bad or odd. When the odd transponders pop up they have values in the 80's while the even transponders have values from 89-95. But they come and go to "blank" as if the signal drops out. But I can invoke "low Res" mode and then it usually works at low resolution video.

My dish was aligned a few months ago when a DTV tech came over to fix this problem. At that time the problem was more intermittent and I wasn't able to show him. Now its worse. They are coming back in a few days and I was hoping I could get more info as last time the tech wasn't interested in even trying and wouldn't even get on my roof as he said "he couldn't". I'm not sure how one checks the 20 year old LNBs without getting on my roof as he aligned the dish hanging off a ladder.

Its very specific to certain channels and I mention CNBCHD ( Sat 103B no transponder) because it fails almost constantly now. It must be associated with a satellite, LNB, RF leakage from nearby WIFI etc, or something that hits certain channels and not most. The connectors are tight. Any thoughts appreciated. I just don't have much confidence with a DTV tech after my last experience. I've been with DTV for over 20 years and when ATT bought them, their service fell apart. At $250/mo with 4 receiver insurance - its bad!

Does anyone know how the mapping works plus why the odd transponders on 103(cb) would be flaky and if so does this mean a bad transponder or feed voltage up the coax?

My system looks about like this picture I found:

[​IMG]

Thanks for any ideas?

shannon02

ACE - Expert

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16.5K Messages

8分前

Don't know what happened to your other post but here is the same answer.   Due to new OSHA rules techs are no longer allowed on the roof so they need to install a new dish where it can be service.  I doubt the tech aligned the dish.  DTV's basic insurance plan is $8.99 a month that covers service calls and shipping of replacement receivers and remotes regardless of how many receivers you have.

(edited)

TexasBrit

ACE - Expert

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13.8K Messages

8分前

If you have an swm lnb (single cable from the dish as you show in the diagram)this could be poor dish alignment or a faulty LNB. If you have the old LNB with four cables from the dish this could also be a faulty cable/connector. 

If your dish can't be accessed under OSHAP rules you would need a new dish to be installed where the tech can access it without climbing on the roof. Whatever the situation, you will need a directv tech visit to sort this out.

New Member

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10 Messages

8分前

I was hoping to get an explanation of the relationship between channel/transponder and LNBs and coax cables so I could track the problem down myself if possible.

I have the old style LNBs with 4  coax cables from the dish. I have 1 HR34-700, 2 HR24-500 and 1 HR22-100 receivers.

My whole home visibility is also intermittent. By this I mean sometimes a receiver loses visibility to other receiver recordings which cannot be corrected with a receiver reset.

I have checked all the coax connections as tight but the LNBs have been on my roof for 15+ years along with the coaxes.

The system has been flaky for years and the pandemic inhibited me from getting it fixed even though I have paid for the protection plan for 15+ years. Oh well. Its about time to go online.

Anyone found a DVR function as good as DirecTV online? Do he latest DVR receivers use the same interface as mine listed above?

thanks

shannon02

ACE - Expert

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16.5K Messages

8分前

The HR34 requires a SWM system so you had a legacy system with four coaxes so they used one of them for the SWM system.  The HR34 should be replaced as it is to under powered to run the new software.

TexasBrit

ACE - Expert

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13.8K Messages

8分前

As shannon says, the HR34 is an SWM dvr so only one of the cables from the dish is being used, the others are "spare". Since it is an SWM system. all the transponder frequencies come down the same cable so a problem with the cable would not cause just a particular transponder or set of transponders to have an issue. That basically points to the problem being a faulty LNB. 

Problems with the LNB control voltage can only apply to the old style LNBs which are not SWM.

shannon02

ACE - Expert

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16.5K Messages

8分前

It is also possible they have a SWM16 module and all the coaxes are in use but the diagram they sent seems to say only 1 coax in use.

TexasBrit

ACE - Expert

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13.8K Messages

8分前

yes, or 4 cables to an SWM8.  But we are reliant on the OP telling us accurate information since we can't see his installation.

shannon02

ACE - Expert

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16.5K Messages

8分前

He has 9 tuners unless one of the receivers is set to single tuner.  Not sure what is causing the Whole Home to be flaky.

TexasBrit

ACE - Expert

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13.8K Messages

8分前

Actually he has 10 tuners, so there must be an SWM16. And if so, the problem is almost certainly the SWM16 or one of the cables from the dish to the SWM16.  We are just not getting the whole picture from the OP.  We can't diagnose this problem without correct information.

New Member

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10 Messages

8分前

I have a 10 channel SWiM16 with 4 cables to the old style LNB.

https://images.app.goo.gl/LDbu44ENYEep5VYN7

I have 2 HR24-500, 1 HR34-700 and 1 HR22-100.

shannon02

ACE - Expert

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16.5K Messages

8分前

Dish alignment is the number one cause of the 771 error code and since DTV no longer can go onto the roof I doubt the tech you had aligned it.  You are using 11 tuners from the SWM16 module the HR34 uses 5 the HR24 and the HR22 all use 2 each so 5+2+2+2=11

(edited)

TexasBrit

ACE - Expert

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13.8K Messages

8分前

The situation is just more than complicated by the use of the swm16 and the way in which the differernt satellites and transponders are mapped to the four cables from the dish. I could spend several paragraphs explaing how this all works but it does not really matter since you can't get to the dish. You really need to get rid of the legacy dish, LNB, multiswitch and cabling. JUst schedule  atech visit.THe tech will put the dish somewhere else that meets the oshap  requirement, run one cable to the house, put a power inserter and splitters in the house. Tell him the HR34 isn't working properly and you'll probably get an HR54. . 

New Member

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10 Messages

8分前

Thanks. The tech is coming Thursday. I have a Telecom systems engineering/software background as my company was bought by General Instruments in 1995 and was also curious how they mapped satellites,  transponders, RF channels, downlinks, video/audio packets, LNBs, cables and tuners etc... Its probably a mess given what I've seen so far. The internet is so much easier... Its such a dinosaur - need a new comet 65million late!


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