"Cannot detect SWM" with installed cables

Discussion in 'DIRECTV General Discussion' started by weiser701, Jul 1, 2017.

  1. WestDC

    WestDC Well-Known Member DBSTalk Club

    3,577
    392
    Feb 9, 2008
    Quick test would be to connect the LNB to the PI- Then using a made rg6 jumper connect it to the (PI) IRD then to a Receiver -if it works LNB is okay - Inside wiring is suspect
     
  2. HoTat2

    HoTat2 Hall Of Fame

    7,975
    279
    Nov 16, 2005
    Los...
    But that's what has already been determined, that the newly pre-installed inside wiring through the house walls is the problem for carrying SWM satellite signals anyhow.

    When the OP bypasses the inside wiring with a 100' RG-6 cable to the dish everything works fine as he explained in the initial post. But he wants to get the inside house cabling to work for obvious reasons and can't figure out why it doesn't work for satellite signals when OTA signals seem to pass through it with no problem.

    Sent from my LGMS550 using Tapatalk
     
  3. eakes

    eakes Godfather

    354
    2
    Sep 21, 2007
    The OP has stated that all works when a 'test' cable is used from dish to splitter to PI and then to a receiver. The problem occurs when trying to use the 'in-wall' cable instead of the test cable. Using the in-wall cable results in an error message that basically says "can't find the SWM".

    When measuring voltage at the dish with the PI connected directly to the in-wall cable, the meter is reading a variable voltage which goes above the nominal 29V of the PI. I suspect he is using a DVM and holding the test leads to the shield and center conductor with his fingers. With no actual voltage reaching the dish from the PI the meter is reading spurious signals picked up by his body. An open coax can still act as an antenna for OTA signals so the 'TV test' really means nothing.

    The coax was obviously damaged during construction. It is likely at least partially open. Finding the location of the problem will likely be difficult. Hopefully, it can be used as a pull cord to drag in a new coax.
     
    HoTat2 likes this.
  4. HoTat2

    HoTat2 Hall Of Fame

    7,975
    279
    Nov 16, 2005
    Los...
    My thinking aa well ....

    Sent from my LGMS550 using Tapatalk
     
  5. WestDC

    WestDC Well-Known Member DBSTalk Club

    3,577
    392
    Feb 9, 2008
    I would then suggest - Checking the Coax Ends -for strands since the inside walls will be impossible to fix -without opening them or re-running exposed wires or Going with a Wireless bridge wherever possible
     
  6. doctor j

    doctor j Hall Of Fame DBSTalk Club

    1,779
    65
    Jun 14, 2006
    Birmingham, Al.

    Unfortunately , he's tried that also. See post #4
    "I installed all new compression connectors and I'm still getting the same "Cannot detect SWM" message."

    I agree the OTA is a 'red herring'.
    An inexpensive cable tester may confirm the bad cable but I don't think there is any other explanation.
    A NEW cable run, however unpleasant, is in order.

    Doctor j
     
    WestDC likes this.
  7. WestDC

    WestDC Well-Known Member DBSTalk Club

    3,577
    392
    Feb 9, 2008
    The Op Options are to work with the builder on a Refund/Repair for the wiring applied to the Electric Co the re-fish all locations and patch any holes that need to be cut - Depending on the Contractor that installed the RG6 if the Elec contractor Did then the expense is on them - He should at least have a min of a 1 year Whole home warranty on NEW Construction.
     
  8. inkahauts

    inkahauts Well-Known Member

    24,929
    1,536
    Nov 13, 2006
    I don’t know, it’s never been clear to me exactly what cables he has bypassed in the system. All of them, one of them, and if one of them or two of them which ones?
     
  9. HoTat2

    HoTat2 Hall Of Fame

    7,975
    279
    Nov 16, 2005
    Los...
    1) ODU with SWM LNB ----> pre-installed in-wall house coax wiring ----> 4-way SWM splitter in wiring closet ----> 29v PI ----> HR24

    2) Same as above, but this time bypassing the in-wall house coax wiring with a 100' run of RG-6 cable as a test.

    #1 is the installation the OP wants, but can't get to work, at least not for satellite signals. Receiver always gives a "cannot detect SWM" error message.

    #2 the test install bypassing the house wiring works fine. That is, when placing a 100' coax between the SWM splitter and the ODU.

    Sent from my LGMS550 using Tapatalk
     
  10. weiser701

    weiser701 New Member

    7
    0
    Jul 1, 2017
    Thanks everyone for the robust discussion. I'm still working on this. The electrician is supposed to be out here next week.

    One reason why I tossed out the idea that the cables aren't adequate is that they came off the same spool my brother and I used to wire his house. Directv with SWiM comes in just fine there, with various length runs including some fairly long. However, is there any way to compensate for CCS coax or is the only option to run new cables? Wouldn't the main impact be the run from the PI to the LNB?

    "I suspect he is using a DVM and holding the test leads to the shield and center conductor with his fingers. With no actual voltage reaching the dish from the PI the meter is reading spurious signals picked up by his body."
    I actually was being careful NOT to do this for this exact reason. Also, I'm using the same procedure and practices used to measure with the troubleshoot cables where I'm getting the proper voltage.
     
    Last edited: Jul 6, 2017
  11. weiser701

    weiser701 New Member

    7
    0
    Jul 1, 2017
    I guess what baffles me most is that I've isolated the connections to where I tried these two scenarios without success:

    Troubleshoot cable connected for [PI --> LNB] and in-wall cable for [PI --> HR24 receiver]
    In-wall cable connected for [PI --> LNB] and troubleshoot cable for [PI --> HR24 receiver]

    At this point it seems to be coincidence neither works since I would think at least the scenario using the <50' in-wall run from the PI to receiver should have it working. This is using the Directv supplied troubleshoot cable for PI --> LNB.
     
    Last edited: Jul 6, 2017
  12. WestDC

    WestDC Well-Known Member DBSTalk Club

    3,577
    392
    Feb 9, 2008
    Oder one of these - and take the guess work out of it!

    4 Way Coax Cable Mapper Tracker Toner Tracer Finder RG6 RG59 Tool Perfect Vision - - Amazon.com
     
  13. slice1900

    slice1900 Well-Known Member

    10,811
    1,578
    Feb 14, 2013
    Iowa
    There's probably a nail through the coax...
     
  14. eakes

    eakes Godfather

    354
    2
    Sep 21, 2007
    Another test you can run: at the dish connect the in-wall cable to the test cable (using a F-F adapter), then in the house check for continuity of both the center conductor and the shield. Also check for continuity between the center conductor and shield of the in-wall coax (should be open).

    As to the DVM readings: with a voltage present the meter will read that voltage, however if there is no voltage to read the test leads can 'read' almost any and everything.

    As an aside: years ago I was installing a length of RG-8 taken from a large spool of said cable. I found that there was no continuity of either the center conductor or the shield. Upon inspection of the cable to find the problem, I found a spot where the diameter did not 'feel' right. I opened the jacket and discovered two 'ends' of the cable that were not connected - somehow during construction of the cable two separate pieces of cable were 'joined' with the cable jacket - but nothing else!
     

Share This Page

spam firewall