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Scott911's avatar
Scott911
Tutor
Dec 28, 2019

Netgear CM1100 Continually Rebooting

Hi,  I have had a rough time with a New CM1100 i bought from Costco.  I have Spectrum and once the modem was installed and activated it started rebooting every 2-3 minutes and was not functional.  I ...
Scott911's avatar
Scott911
Tutor
Dec 30, 2019

Attached is my Modem data.  I am using a Asus CM-16 as I had to remove the Netgar CM1100 for the network to work.

Thanks for the assistance

 

plemans's avatar
plemans
Guru - Experienced User
Dec 30, 2019

You've got line issues. You've got errors on your incoming line with it being a bit high and your upstream strength is way to low. Minimum is 35 dBmV with 45 dBmV being ideal for upstream. Probably why the CM1100 wouldn't connect as it needs a decent upload. 

I'd have your ISP check your line. 

  • Scott911's avatar
    Scott911
    Tutor
    Dec 31, 2019

    Thanks - I will call spectrum.  I wonder if the splitter can help?  The splitter is a Extreme BDS103H and 5-1002 MHZ, and the modem is connected to the -7db, maybe I should try the -3.5db?

    • plemans's avatar
      plemans
      Guru - Experienced User
      Dec 31, 2019

      First thing I'd do is move the modem to right where the line enters the house. directly connect there with no splitters. 

      Then check your power levels. and post them here. 

      A bad splitter/cheap splitter/etc can cause all kinds of issues. 

      If you're running cable tv and a modem it should always go    incoming line-------double splitter with one lead to modem and another to either to a tv or another splitter for your tv. for the time being, remove all splitters and see what happens with the signal. 

      • TheRealSpinner's avatar
        TheRealSpinner
        Aspirant
        Jun 15, 2020

        I am having the same rebooting problems with my brand new Netgear CM1100 (Costco) Cable Modem.

         

        A year ago I purchased the Netgear CM1000 Cable Modem from Costco.  I was going to replace my Netgear CM600 which is rock solid with Cox Communications.  Purchased the CM1000 to get Gigablast.  This ended up in failure.  CM1000 would not keep connection kept rebooting.  Cox Technician came out and replaced part at the Node across my street.  Tried to get a stable connection with CM1000 no luck kept rebooting.  I gave up and went back to the CM600 (Rock Solid).

         

        Purchased the CM1100 after returning the CM1000.  Decided to give it another shot with the New Netgear CM1100 and Cox Communications.  Same crap is happening again.  CM1100 is rebooting again and again.  Gave up again and went back to CM600 (Rock Solid).  Cox Technician is coming out Wednesday.

         

        What could be the problem?

         

        I do have an old splitter that Cox Communications installed in my attic that splits the coax cable (from outside of house) to existing coax outlet in office and to coax outlet in closet where all network equipment is installed.  Cable Modem, Router, Switches, etc.

         

        I have attached an image of my existing Netgear CM600.

         

        Any help would be appreciated.