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thenixhex311's avatar
thenixhex311
Aspirant
Jun 07, 2021

Constant disconnects - Xfinity cant detect signal - Netgear CM1150V Modem

Oh man, that was frustrating...i had the whole thing typed...switched to HTML and I lost it all. Have a Netgear CM1150V modem with Xfinity Gigabit. Purchased it in Feb. Constant connection issues as o...
FURRYe38's avatar
FURRYe38
Guru - Experienced User
Jun 07, 2021

Have the ISP check the signal and line quality UP to the modem. Be sure the ISP provisions the modem correctly.
Be sure there are no coax cable line splitters in the between the modem and ISP service box. 
Be sure your using good quality RG6 coax cable up to the modem. 
Be sure to power OFF the modem for 1 minute them back ON.
https://community.netgear.com/t5/Cable-Modems-Routers/General-info-and-Troubleshooting-for-Cable-Modems/m-p/1530376#M12853
https://highspeed.tips/docsis-events/

What brand and model is the wifi router connected to the CM modem? 

 

  • thenixhex311's avatar
    thenixhex311
    Aspirant
    Jun 07, 2021
    My router is a NETGEAR - Orbi AX4200
    Just got it Friday
    • FURRYe38's avatar
      FURRYe38
      Guru - Experienced User
      Jun 08, 2021

      Ok. Make sure the ISP gets good service and signal to the modem first. Hopefully they can figure out the problem on there side. 

      • thenixhex311's avatar
        thenixhex311
        Aspirant
        Jun 10, 2021

        ok, so an Xfinity guy came out Tuesday and did a test at the outside connection of the house. There was a 3-way splitter he replaced. One line runs into the house that goes to a DVR cable box. Two other lines run up the house behind the gutter, one going to where the modem is, the other eventually to the master bedroom is. Once he disconnected the line that ran to the bedroom, he said the noise 'hump/spike' in the line went away. We switched that out for a wi-fi secondary tv box instead of the hardwired one.

         

        Yesterday had no problems at all.  Today, my wife (works from home) said she's had to disconnect it twice. Only new variable is that my son is home from my in-laws now.  I have him and my daughter BOTH on Chromebooks and BOTH on Roku TVs.

         

        Wife just checked the modem Event Log and this was our recent stuff, stil has T3 errors (see examples below).

        Is this still potentially a modem issue/something with Xfinity, or maybe just network congestion? She also just noticed the modem is set to central time (i'm translating/relaying over chat) and we are Eastern, is that an issue?

         

        CRITICAL (3)   Started Unicast Maintenance Ranging - No Response recieved - T3 time-out; CM-MAC=08:36:c9:37:eb:50;CMTS-MAC=00:f3:c8:05:e5:5d;CM-QOS=1/1;CM-VER=3.1

        WARNING(5) Dynamic Range Window violation

         

        WARNING(5) RNG-RSP CCAP Commanded Power Exceeds Value Corresponding to the Top of the DRW;CM-MAC=08:36:c9:37:eb:50;CMTS-MAC=00:fe:c8:05:e5:5d;CM-QOS=1.1;CM-VER=3.1;

         

        CRITICAL(3) No Ranging Response recieved-T3 time-out;MAC=08:36:c9:37:eb:50;CMTS-MAC=00:f3:c8:05:e5:5d;CM-QOS=1/1;CM-VER=3.1