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SethSea's avatar
SethSea
Tutor
Nov 21, 2023
Solved

CM2050V goes offline every few weeks - how to troubleshoot

My Netgear Nighthawk CM2050V cable modem, purchased earlier this year, linked to Comcast service has been going offline every few weeks for the past two months.  Comcast cannot find an issue. Powerin...
SethSea's avatar
SethSea
Tutor
Nov 22, 2023

Attached of event log export in binary format with "gif" extension failed on Post.

 

Please let me know if you need any additional information.

 

I appreciated the links to "how to" articles.

 

Thank you 

  • FURRYe38's avatar
    FURRYe38
    Guru - Experienced User
    Nov 22, 2023

    So power levels are good along with Correctables and Un-Correctable values. 

     

    Any Criticals, Errors or Warnings seen in the event logs needs to be reviewed and resolved by the ISP. Indicates a signal issue on the ISP line up to the modem.


    Be sure your using a good quality LAN cable between the modem and router. CAT6A STP is recommended. 
    What is the brand and model of the host wifi router connected to the modem?

     

    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. 
    Start with removing any amplifiers, signal attenuators, or splitters from the coax.
    From there check the line for kinks, damage, moisture in the line.
    Check the connectors for improperly made ends, foil touching the copper coax line, loose connections, bad/old/cheap connectors, or corroded connections. Replace them if you do.
    Be sure to power OFF the modem for 1 minute then back ON.
    https://community.netgear.com/t5/Cable-Modems-Routers/General-info-and-Troubleshooting-for-Cable-Modems/m-p/1530376#M12853
    https://kb.netgear.com/24311/Power-level-guidelines-for-a-NETGEAR-cable-modem-router
    https://www.duckware.com/tech/solving-intermittent-cable-modem-issues.html
    https://highspeed.tips/docsis-events/

    • SethSea's avatar
      SethSea
      Tutor
      Nov 27, 2023

      Thank you for taking the time to provide a detailed response. The Duckware link was particularly helpful.

       

      I would appreciate your opinion on where the problem lies - hardware, ISP, software, other? I do not want to buy a new cable modem to find out it does not solve the problem

       

      Before posting to this site, I contacted Comcast. They performed tests from the host side and said the connection looked good. A serviceman came out and said the connection looked good at the modem and suggested replacing the CM2050V with another one. I have looked through the modem logs and see a couple of critical errors that happen every now but they do not seem to be interfering with the modem - despite the errors I have not experienced any problem and the modem has stayed online.

       

      I have attached a "Cable Info" report from this morning. Do you see issues that I should contact Comcast about? As far as I can tell, other than the critical errors (maybe benign), everything looks great (following the troubleshooting in the Duckware article).

       

      As I purchased this modem earlier this year, I cannot get Netgear support without buying a contract.

       

      Again, thank you for your advice.