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Luapski's avatar
New Contributor
2 months ago

Should I get a new cable modem?

I've been having some trouble with my home Internet service this past week. Service kept dropping for a few minutes then resuming.

A Cox technician came out yesterday and found an old splitter buried in a wall that seemed to have been part of the problem. He scanned the upstream line and also found that my line had significant interference.

He broke me off a clean drop and verified that it was clean between the Cox box and my home, and I installed a fresh new quad-shielded piece of pre-terminated RG6.

Here's the issue: If I look at the cable modem logs, I'm still getting constant errors. While I've read that Code 16 errors on channel 159 are no big deal and can pretty much be ignored, I'm not so sure about the dynamic range window errors.

I've been running a ping out to Google DNS since installing the new line and, while the shut downs don't seem noticeable anymore, there are instances where the network goes down for something like 13 minutes.

Below are screenshots of the stats from the cable modem. Overall, the signals appear to be in range. But, I wonder if this level of erroring indicates that this modem is hosed?

It's a Motorola CM1100.


1 Reply

  • WiderMouthOpen's avatar
    Esteemed Contributor

    Have you tried bypassing the router and connecting via ethernet direct to the CM1100 modem? Does the modem logs timestamps match up with when you lose service? The only critical warning I see is the last one. UCD stands for Upstream Channel Descriptor so it appears a issue with the upstream. Most of the errors are event error 16/24 which is on/off issues with the first downstream OFDM channel. I think those are "normal". The Dynamic Range Window Violation is usually paired with a T3 error(which is a upstream noise issue) so I think your issue is defiantly upstream.

    While it could be a modem issue, my experience is it is rarely that. If you do buy a new modem make sure it is returnable if it doesn't solve the problem. Otherwise, try tracking the packet loss with Pingplotter and schedule another technician.