CM2050V unstable after Comcast updated firmware

[ATB]

I have the same issue with two CM2050V modems at two locations (one in Massachusetts and another in California). I have Xfinity triple-play service (Gigabit Internet option). After the modems have been upgraded to V9.01.01, they get stuck every 2-3 weeks and require power cycling. I ended up installing timers, so the modems got power-cycled every night.  I hope Comcast / Netgear fixes this issue soon!

[FURRYe38]

Please post a copy and paste of the modems connection status and event log page.
https://kb.netgear.com/30007/How-do-I-obtain-the-cable-connection-information-from-a-NETGEAR-cable-m...
https://kb.netgear.com/30008/How-do-I-view-or-clear-the-event-logs-on-my-NETGEAR-cable-modem-or-mode...

FYI:

https://community.netgear.com/t5/Cable-Modems-Gateways/Nighthawk-CM2050V-Comcast-Firmware-Killed-Spe...

[ATB]

I have tried twice already to reply to your request for log files and somehow it does not get posted.

[FURRYe38]

Can you copy the data into a wordpad or word doc then export to PDF file then attach that file to your next post?

[ATB]

here we go:

[FURRYe38]

Modem 2s power is good. Need to see Event log if possible, however if event log looks similar to modem 1, then Any Criticals, Errors or Warnings seen in the event logs needs to be reviewed and resolved by the ISP. Indicates a signal issue on the ISP line up to the modem.
Be sure your using a good quality LAN cable between the modem and router. CAT6A STP is recommended.  

Modem 1 power levels on the higher channels are too high:

https://kb.netgear.com/24311/Power-level-guidelines-for-a-NETGEAR-cable-modem-router

MIght put a coax line splitter in to see if this can help. 3db splitter. 

Have the ISP check the signal and line quality UP to the modem. Be sure the ISP provisions the modem correctly.
Be sure there are no coax cable line splitters in the between the modem and ISP service box. 
Be sure your using good quality RG6 coax cable up to the modem. 
Start with removing any amplifiers, signal attenuators, or splitters from the coax.
From there check the line for kinks, damage, moisture in the line.
Check the connectors for improperly made ends, foil touching the copper coax line, loose connections, bad/old/cheap connectors, or corroded connections. Replace them if you do.
Be sure to power OFF the modem for 1 minute then back ON.
https://community.netgear.com/t5/Cable-Modems-Routers/General-info-and-Troubleshooting-for-Cable-Mod...
https://www.duckware.com/tech/solving-intermittent-cable-modem-issues.html
https://highspeed.tips/docsis-events/

[ATB]

Thank you for your suggestions. However, both modems worked fine without "hanging" for over two years until the recent firmware upgrade. No changes have been made to the wiring and my ISP service plan. Again, after the firmware upgrade, the issue is that the modem hangs every 2-3 weeks and the only remedy is to power cycle it. 

I can produce a similar hanging issue when logging into the modem, and going to ADVANCED, Administration.

When I click on "eMTA Event Log", the modem hangs and the only remedy is to power cycle it.  Thus, I suspect that these hanging issues are related to the recent firmware upgrade. Please advise. 

[FURRYe38]

Modem 2s power is good. Need to see Event log if possible, however if event log looks similar to modem 1, then Any Criticals, Errors or Warnings seen in the event logs needs to be reviewed and resolved by the ISP. Indicates a signal issue on the ISP line up to the modem.
Be sure your using a good quality LAN cable between the modem and router. CAT6A STP is recommended.  

Modem 1 power levels on the higher channels are too high:

https://kb.netgear.com/24311/Power-level-guidelines-for-a-NETGEAR-cable-modem-router

MIght put a coax line splitter in to see if this can help. 3db splitter. 

Have the ISP check the signal and line quality UP to the modem. Be sure the ISP provisions the modem correctly.
Be sure there are no coax cable line splitters in the between the modem and ISP service box. 
Be sure your using good quality RG6 coax cable up to the modem. 
Start with removing any amplifiers, signal attenuators, or splitters from the coax.
From there check the line for kinks, damage, moisture in the line.
Check the connectors for improperly made ends, foil touching the copper coax line, loose connections, bad/old/cheap connectors, or corroded connections. Replace them if you do.
Be sure to power OFF the modem for 1 minute then back ON.
https://community.netgear.com/t5/Cable-Modems-Routers/General-info-and-Troubleshooting-for-Cable-Mod...
https://www.duckware.com/tech/solving-intermittent-cable-modem-issues.html
https://highspeed.tips/docsis-events/

[Kitsap]

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@ATB wrote:

Thank you for your suggestions. However, both modems worked fine without "hanging" for over two years until the recent firmware upgrade. No changes have been made to the wiring and my ISP service plan. Again, after the firmware upgrade, the issue is that the modem hangs every 2-3 weeks and the only remedy is to power cycle it. 

I can produce a similar hanging issue when logging into the modem, and going to ADVANCED, Administration.

When I click on "eMTA Event Log", the modem hangs and the only remedy is to power cycle it.  Thus, I suspect that these hanging issues are related to the recent firmware upgrade. Please advise. 

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The recent firmware update is only one piece of the puzzle.  Several users have reported that after the firmware update, their modem was not properly provisioned by Comcast.  That is an issue you will have to take up with Comcast support to confirm your provisioning is correct.  You may have to go to tier 2 support to get that done.

[ATB]

What would be the symptoms that it is not properly provisioned by Comcast? I find it hard to believe that this would happen at two different locations (in California and in Massachusetts). Also, this does not explain the bug that I described above that cause the modem to hang. 

[Kitsap]

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@ATB wrote:

What would be the symptoms that it is not properly provisioned by Comcast? I find it hard to believe that this would happen at two different locations (in California and in Massachusetts). Also, this does not explain the bug that I described above that cause the modem to hang. 

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Symptom, the modem is not working as expected.  Like maybe it is hanging after a while.

Reports indicate the firmware push was made over a wide area.  The only thing you can do is to call support and request they confirm your modem is properly provisioned.  There is a chance tier 1 support may not recognize the issue.

[ATB]

Do you think the provision checking will eventually be done by Comcast automatically without calling them? 

[FURRYe38]

Call and ask for escalated support. 

[Kitsap]

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@ATB wrote:

Do you think the provision checking will eventually be done by Comcast automatically without calling them? 

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Possibly if the modem is connected in an area that converts to the mid-split 10G network.  Nothing you can count on from a time frame perspective.

[ATB]

OK. Thanks. I used the "Agent Chat" and simply requested to reprovision the modem, stating your recommendation. They recommissioned both modems. 

Is there some diagnostics that I can run to make sure that this solves the issues I had?

[Kitsap]

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@ATB wrote:

OK. Thanks. I used the "Agent Chat" and simply requested to reprovision the modem, stating your recommendation. They recommissioned both modems. 

Is there some diagnostics that I can run to make sure that this solves the issues I had?

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Just run them over time and see if the problems reoccur.  If they do reoccur, there are a couple of Comcast direct forums where you can post and ask for assistance from Comcast employees.  On either forum, the employees are responsive and technically very competent.

https://www.dslreports.com/forum/comcastdirect

https://www.reddit.com/r/Comcast_Xfinity/

[ATB]

Thanks. In addition to re-provisioning the modems, I addressed the relatively high downstream power levels for one of the two modems (some were above 10 dBmV). All lines are connected to an amplified splitter in our condo building. I connected my line to the VoIP line, and the downstream power levels are now within the good range (about 5 dBmV). So far, no problems anymore. 

[ATB]

The problem (modem trying to reconnect over and over again) happened again this morning shortly after the automatic switch to daylight standard time. Could this be yet another glitch in the new firmware?  Attached is the log file after I power cycled the modem.

[FURRYe38]

Any Criticals, Errors or Warnings seen in the event logs has to be reviewed and resolved by the ISP. Indicates a signal issue on the ISP line up to the modem.

[Kitsap]

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@ATB wrote:

The problem (modem trying to reconnect over and over again) happened again this morning shortly after the automatic switch to daylight standard time. Could this be yet another glitch in the new firmware?  Attached is the log file after I power cycled the modem.

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The Comcast servers stay on standard time year around, they do not adjust for daylight saving time.  No issues here with the time change.

Based on the attached status, it appears your power levels are very near the high limit.  The Netgear specification for power levels runs from -7 dBmV to +7 dBmV.  For reference, check out the second sentence at the top of this knowledge base article here:

https://kb.netgear.com/24311/Power-level-guidelines-for-a-NETGEAR-cable-modem-router

Have you considered trying one of these for test purposes?

3db Coax Cable Attenuator Pad (1 Each) https://a.co/d/hyGhBWn

[ATB]

The new firmware was also pushed yesterday to my two CM2050V modems in two different locations (Massachusetts and California). So far, no issues. 

[FURRYe38]

Glad you got it working. Please mark your thread as solved so others will know. 

Enjoy. 📡

[JustBry76]

Mind sharing the firmware version pushed to your two modems?

[Kitsap]

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@JustBry76 wrote:
Mind sharing the firmware version pushed to your two modems?

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Version that is presently installed on mine is V2.01.03.  This is the version that was installed prior to the push of V9.01.01.

[ATB]

Correct, the firmware they recently pushed to both modems is V2.0.1.03. So, it looks like they reverted to the previous firmware.