Cable modem suddenly going offline intermittently

Discussion in 'Networking' started by WAZ, Jan 5, 2012.

  1. WAZ

    WAZ Golden Member

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    A few weeks ago I started noticing some random disconnects on my cable modem; now lately it's happening about every 20 mins or so. I'm just working or playing a game, and bam, orange light for about 15 seconds. Then it re-connects on its own after a few seconds and it's fine till it does it again... and again...

    I've tried unplugging and rebooting my router, modem, and VOIPo adapter, to no avail. Does this sound like...

    1) A router issue? I just opened a bunch of ports for Battlefield 3 recently; wasn't sure if that could contribute to this in any way, but the timing would be very close and coincidental.

    2) My D-Link modem failing? Need to buy a new one?

    3) An ISP issue? Do I need to get on the phone with Comcast?

    I've had no issues for about 5 years and this JUST started happening, so I don't think anything is mis-configured or anything. Any advice would be great. Thanks! :)
     
  2. amdhunter

    amdhunter Lifer

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    Probably on it's way out. See if you can login to the modem to check signal levels. If they look good (+2dB to -9dB is acceptable), your modem is probably going bad.

    If the signal is bad (way under 7dB) then check your splitters for damage. After 5 years, you'd be surprised how crappy they can get (especially ones outdoors.)
     
  3. gsaldivar

    gsaldivar Diamond Member

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    Is your modem leased with your cable internet service? If so, just take it in and trade it for a new one.
     
  4. MtnMan

    MtnMan Golden Member

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    Well it ain't your router.

    Check connections, have you added any splitters, etc. for new devices. Browse to 192.168.100.1 (addy of most cable modems) and look at log, SNR, signal levels.

    Disconnect and reconnect all connections up to your modem (this creates "new" connections) and is free.

    Of course it could be your modem's last days, especially if it's 5+ years old.
     
  5. ImDonly1

    ImDonly1 Platinum Member

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    Post the signals here like the above guy said. Go to the signals page and post them here. Some of the logs might help too, but edit your MAC address out if you do post the logs.
     
  6. WAZ

    WAZ Golden Member

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    Awesome, thanks for the tips guys. I'll check the signals and outside splitter this weekend. :)

    I own the modem (not lease)... actually it's probably closer to 6 or 7 years old, now that I think of it... so if that is the problem then I will have to buy a new one. Probably about the same price as a Comcast service call, so it'd be good to find out myself. Thanks!
     
  7. gsaldivar

    gsaldivar Diamond Member

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    These days most service (DSL, Cable) includes a modem in the cost of the service. Just tell them that you are having chronic connection problems, and that you have an advertisement in front of you for a different provider where they are offering you a free modem.

    Watch how quickly they ship you a free modem... :cool:
     
  8. ImDonly1

    ImDonly1 Platinum Member

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    Never seen that. I have seen $7/mo rental fees though.

    If you must buy a new one, slickdeals had a thread about getting the SB6121 Docsis 3 modem for I think $58 or $68 at Staples.
     
  9. gsaldivar

    gsaldivar Diamond Member

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    6-7 years ago, modem lease fees were common. They are quite rare now. ISP might require purchase only for a month-to-month account, but anything with a year term is almost always free install + free equipment. Even with a term commitment, you can always use a competing ISP's promotion to bargain for a free modem and/or discount from your current provider...
     
  10. VirtualLarry

    VirtualLarry Lifer

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    Comcast, one of the largest nationwide cable providers, still charges $6/mo for cablemodem rental in the NE area.
     
  11. MtnMan

    MtnMan Golden Member

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    Charter increased the $5/month lease to $7/month several months ago, even sent out a letter that they were increasing the monthly lease. Owned my own modem for years.