Arris SB6400 Modem keeps resetting

CrejaudCrejaud Posts: 3 ✭✭
edited November 20 in Connectivity Nov 20, 2020

I currently have my Arris SB6400 router/modem acting as a modem (with wifi turned off). This modem is restarting daily at odd times. It seems like a full reset the modem status up time seems to align with when it last restarted

Here are the event logs around when it rebooted

Here is the connection status right now (hasn't rebooted in 11 hours):

I have been dealing with random reboots for years at this point, and every time I talk with Spectrum or the Manufacturer, they are unable to help.

Would someone know if these signals look okay? Is this a configuration problem with my modem?

EDIT: I have also tried replacing my Arris SB6400 modem with a Netgear Nighthawk Modem that is compatible with my internet connection, and it restarted way more often that with my Arris SB6400, so I reverted back to the Arris SB6400


  • Lake802Lake802 Posts: 48 ✭✭✭✭
    edited November 21 Nov 21, 2020

    Hello Crejaud - sorry to hear you are having modem issues. The detailed shots you provided were most helpful. Those screen shots show recurring T4 errors and uncorrectable errors incrementing slightly.

    Swapping modems is a good first round diagnostic step but as you can see didnt make a substantial difference. That is primarily because the likely source of those T4 errors is usually cabling or connectors upstream from the modem. Would encourage you to contact Spectrum technical support and schedule an onsite dispatch. Ask them to correct the "source" of the recurring T4 errors in addition to making sure your other modem stats (RX, TX, SNR) are in spec.

    Once those T3/T4 errors are corrected - the reboot aerobics with the modem will no longer be a part of daily life.

    Please let us know how it goes after your onsite service call.

  • misterjmisterj Posts: 118 ✭✭✭✭
    Nov 21, 2020

    Crejaud, some Modems allow the user to set or boost the upstream power. If either of yours allows this, then I suggest you try to increase the upstream power. Enjoy, John.

  • Lake802Lake802 Posts: 48 ✭✭✭✭
    edited November 21 Nov 21, 2020

    Greetings Crejaud - in general any settings regarding upstream power levels are not user accessible on an ISP cable modem. The up stream levels are calculated and controlled on the other end of the connection at the CMTS (essentially the hub where all the houses in your neighborhood link up to).

    Since every house is at different distance from the hub, different splitters, connectors, quality of coax ,and have different signal characteristics - the power levels get adjusted automatically .

    There are certain modems that support a feature known as "extended upstream transmit power" but is still generally not a user configurable setting.

    If you could access up stream power setting , you wouldnt have a factual basis or frame of reference as to which levels would be optimal for your unique circumstances.

    The Spectrum technician have access to a relatively sophisticated signal meter that will help them to correct signals and optimize them for your location.

    Please let us know how it goes after your service visit.

  • karlbeckmankarlbeckman Posts: 2,231 ✭✭✭✭
    Nov 23, 2020

    Crejaud, an ARRIS SB6400 does NOT appear on Spectrum's list of approved internet devices. However (thinking you copied the number wrong), the SBG6400 is authorized by Spectrum for a network user downstream connection of 100 Mbps or less. If your alternate Netgear modem was set up for a higher speed, you should call Spectrum and re-register the SBG6400 at no faster than 100 Mbps.

  • Lake802Lake802 Posts: 48 ✭✭✭✭
    Nov 23, 2020

    Greetings Crejaud - Karl makes a good point that there is merit to verifying whatever modem you have is match to appropriate provisioning and speed tier. However - , with the info you provided and the presences of recurring T4 errors - the exact model modem doesnt matter much.

    Most neighborhoods have been bumped to a 200Mbs minimum speed tier. A service call can get the pesky T4 errors corrected, They will likely check your cabling and connectors and update you to current modem. The SBxxxx can be safely retired and you will likely have much better stable reliable service with the new set up.

    Please let us know how it goes after your service visit.

  • CrejaudCrejaud Posts: 3 ✭✭
    Nov 23, 2020

    Hi. Thank you all for the quick responses. Here are some extra notes:

    • It is in-fact an SBG6400, not SB6400. That was a typo on my end.
    • I believe I started seeing issues when my internet speed was increased from 100~ Mbs to 200 Mbs, so Lake802's comment seems to line up.
    • I've went to the spectrum store to pickup a free 200 Mbs modem and swapped my current modem. So far no issues! *fingers crossed*
    • I can't seem to log into this modem to check any signals. Maybe because it's a spectrum owned modem. If I start seeing issues with rebooting again, I will schedule a service visit to review the signals of my modem to see if anything needs to be adjusted.
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