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Should I be concerned of my downstream going to -8 dBmV?

antant Posts: 693
in Connectivity Aug 01, 2018



From http://forums.timewarnercable.com/t5/Connectivity/FYI-basics-of-signal-power-level/td-p/116692 guide, -8 is borderline. I know temperatures can also affect this since it is hot with the summer. It was mid 90F degrees outside and almost 90F degrees in my room where the hot cable modem is. Attic and walls would be much hotter where the coax cable lines are hidden.

There was one recent short outage on Sunday when the cable Internet connection went down, and the cable modem decided to autoreboot by itself. DVR's cable digital TV was still working though when I checked during this outage. Logs of that short outage.


Cable modem's logs and statistics can be found in https://paste2.org/h0mzPa39 (couldn't copy and paste into here due to the forum's 20K characters limit -- boo!).


  • RAIST5150RAIST5150 Posts: 650 ✭✭✭✭
    Aug 01, 2018
    More concerned about the potential T-Mobile ingress... lines are getting noisy and dropping out within in their 600MHz spectrum (AT&T and Verizon use 700MHz). Seeing more and more signs that LTE is coming back to bite us in the rear again.

    Inspect your cable runs the best you can for signs of undue stress (sharp turns/kinks or twisted cables, wear and tear from exposure to the elements and such), loose/dirty connections, potential for moisture to get into cables/equipment, etc. Make sure all connections are slightly more than finger tight, there is proper grounding at at least one of the splitters or extender blocks, and there are no active cables/jacks with nothing attached to them--if there is a signal on the line it needs to either have an actual electronic device connected or a termination cap (not just a screw-on "dust cover"... is an actual electronic circuit, so should see a center conductor).

    Will be worth making note of the splitters in play against how many active lines are needed as well. There may be some unnecessary splits in play, which may allow you to reduce signal loss for the modem by switching to smaller splitters, or perhaps even a tap device instead of a splitter if the cable company feels it is warranted.
  • karlbeckmankarlbeckman Posts: 2,206 ✭✭✭✭
    Aug 01, 2018

    I doubt that you have a signal level problem attributable to the temperature in your attic.  I would be more concerned about the several RCS Partial Service messages in the event log.  These indicate that your data modem is unable to receive information on one or more of the DS channnels assigned to it for internet data communications.  It's time to call Spectrum and arrange a home tech service visit.  The tech will attempt to determine why those channels are dropping out at your location. 

    HINT:  Swapping out the modem or replacing the drop cable will NOT fix this problem.  Don't let the service scheduler or home service technician tell you otherwise!   Do NOT let them reset your modem remotely and then cancel your appointment because "your signal levels are back to normal again."

    Chances are that other Spectrum internet subscribers nearby are having similar issues, since the DS channels are shared among all of the cable internet customers in your area.  It takes three users calling in to Spectrum with the same complaint to start a field trouble investigation, so if you try to wait it out or fix it yourself, you are only delaying a restoration of normal connections by the maintenance teams. 

This discussion has been closed.