Question about Arris SB5100 SURFboard DOCSIS 2.0 Cable Modem (50120900100)

1 Answer

Modem reads as online, but doesn't recognize the computers

I have the Motorola modem from Comcast, and I have done all the reset instructions that they give you. The modem seems to be working fine and Comcast shows it as "online", but it is not recognizing the two computers I have it connected to. All the lights are on on the modem, except the light for PC's. I am using a Belkin wireless router, and I have tried plugging the PC's directly into the modem and they still won't recognize them.

What else can I do?

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  • eatmorefish1 Oct 05, 2009

    But even when I plug the ethernet cables into the modem directly it still doesn't recognize the computers and I can't get online. So, I'm not sure that it's the router. Any other suggestions?



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This problem is peculiar with Belkini routers. I got one too till I had to replace with a linksys wireless router.

Sorry about all the stress.

Posted on Oct 05, 2009

  • Onifade Adewunmi
    Onifade Adewunmi Oct 05, 2009

    I would start by re-setting the modem. Disconnect the power for the
    router and modem. Wait a minute or two.

    Plug the modem back in first.
    Wait for the modem to complete communication with your internet service
    provider. When all communication lights are good on the modem then plug
    the power into the router. It amy take a few minutes to get all the

    Hopefully this will allow the DHCP to release from the old
    router and renew to the new one. Make sure if your internet provider
    requires any manual configurations that they are properly configured in
    the new router.

    Please rate this solution.

  • Onifade Adewunmi
    Onifade Adewunmi Oct 05, 2009

    At this point consult the manufacturer and ISP.




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