increasingly frequent "signal loss" w/o apparent cause

[jtiner]

/SNIP/ you definitely don't want to use your T-berd to troubleshoot.

You nailed it.... the T1 and T3 (305?) T-berd was what popped into my head. I used to maintain three DS-3 cross connects feeding telco Rockwell 21130 multiplexers and smaller Fujitsu three channel muxes. Our T3 transport was for proprietary video, but each video T3 had four T1 channels carved out for data. All the T-berds are still in good working condition (even though the network is long gone........).

 

[jtiner]

So I replaced my LNB, and at the same time removed the triplexer from the system so that I have two coax runs from ports 1 and 2 on the LNB to inputs 1 and 2 on the receiver. I performed a check switch, checked signal strength, checked system status (it still reported the exact same LNB drift value of -13), then I let the system go for a couple of days.
The system status changed from "check LNB details" to a different warning to check details, and the report was of signal loss with (multiple reports for time blocks throughout the day for both tuner inputs). The next day the "check LNB" warning was back, with the same value of -13 and a long list of signal losses on both tuners. So far however, I have not witnessed the original problem of encountering the "signal loss" screen when flipping between channels.
I'd really like to know if the LNB drift value and/or the list of signal losses can be trusted. I'm trying to reconcile all of the symptoms with some receiver problem or cable problem (like water infiltration) that's responsible for the odd symptoms. I'm guessing it's highly unlikely I'd have two LNB failures that resulted in exactly the same error message (hex values and 72 e -13). Has anyone had a similar experience?

 

[jtiner]

Just wanted to update this thread since it's referenced in another post.....
I continued to see the LNB drift warning and incrementing count of signal losses, and I lost several recordings due to signal loss.
My final troubleshooting step was to run a new temporary piece of coaxial cable from port 1 on the new LNB to the 722k. I just wanted to rule out water infiltration or other cable damage in my buried conduit. I reset the receiver, then ran a check switch and a new "system info" test. I came up with the same LNB drift value, and had reported signal losses overnight.
I've pretty much resigned myself to the fact that this is (unfortunately) a problem with the reciever itself, but of course I don't have another 722k handy or any other instrumentation that would let me directly measure the LNB output.

 

[mdavej]

Early on in the thread you were asked if you had OTA (an MT2 module for receiving locals from an antenna). That can also cause the symptoms you are seeing even though you may not be using it at the time. Do you have OTA?

 

[jtiner]

Early on in the thread you were asked if you had OTA (an MT2 module for receiving locals from an antenna). That can also cause the symptoms you are seeing even though you may not be using it at the time. Do you have OTA?

No, no OTA module. To eliminate as many variables as possible, I now have the coax runs from ports 1 and 2 on the 1000.4 LNB going to the receiver inputs 1 and 2 (triplexer removed). Each of the runs are ~65' from the LNB to the ground block, then another
~20' to the receiver (no wall plates). I can't say with certainty, but the problem seems less frequent since removing the triplexer but the problem and LNB drift/lost signal counts remain the same.