CM1200 Repeated Disconnects

[Telcontarr]

Hello,
I am experiencing problems with my CM1200 repeatedly disconnecting and reconnecting multiple times unpredictably. I have proceeded with all the usual steps of disconnect and power off, wait ~ 1min, reconnect and power on, etc but still see the issue. Doing some digging it sounds like it might be an power level issue causing the modem to reset? I'm not sure and looking at connection I think things are within spec. I'm attaching screen grabs of my connection information since the table seems to be too large for formatting here. My ISP is Spectrum and I've scheduled an appointment for them to come take a look at my connection but I wanted to check here to see if there was anything I might be missing. Thanks!

[Telcontarr]

The site is apparently not accepting any of my images, trying to repost them. They're in both JPG and PNG formats.

[FURRYe38]

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. 

[Telcontarr]

Thanks! I'll have them check those things, I don't think there are any splitters in the line. 

Do you have a recommendation for a good RG6 cable to use?

[FURRYe38]

The ISP should have good RG6 Coax to use...

[Telcontarr]

Had a second follow up visit on the issue and the Spectrum techs said everything looked fine from their end and saw no router failures, even when there were drops this morning before they got here. I can't determine what's going wrong or where. Here are the event logs if anyone can help me understand what I'm seeing. Tech took a look and said "I can't do anything with your personal equipment". 

Wed Mar 24 10:13:44 2021	Critical (3)	Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=08:36:c9:40:c3:d0;CMTS-MAC=00:17:10:86:bd:cb;CM-QOS=1.1;CM-VER=3.1;
Wed Mar 24 10:13:44 2021	Critical (3)	Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:40:c3:d0;CMTS-MAC=00:17:10:86:bd:cb;CM-QOS=1.1;CM-VER=3.1;
Wed Mar 24 10:13:43 2021	Warning (5)	Dynamic Range Window violation
Wed Mar 24 10:13:43 2021	Warning (5)	RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=08:36:c9:40:c3:d0;CMTS-MAC=00:17:10:86:bd:cb;CM-QOS=1.1;CM-VER=3.1;
Wed Mar 24 10:13:43 2021	Critical (3)	Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:40:c3:d0;CMTS-MAC=00:17:10:86:bd:cb;CM-QOS=1.1;CM-VER=3.1;
Wed Mar 24 10:13:37 2021	Warning (5)	Dynamic Range Window violation
Wed Mar 24 10:13:37 2021	Warning (5)	RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=08:36:c9:40:c3:d0;CMTS-MAC=00:17:10:86:bd:cb;CM-QOS=1.1;CM-VER=3.1;
Wed Mar 24 10:13:37 2021	Warning (5)	Dynamic Range Window violation
Wed Mar 24 10:13:37 2021	Warning (5)	RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=08:36:c9:40:c3:d0;CMTS-MAC=00:17:10:86:bd:cb;CM-QOS=1.1;CM-VER=3.1;
Wed Mar 24 10:13:37 2021	Critical (3)	Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:40:c3:d0;CMTS-MAC=00:17:10:86:bd:cb;CM-QOS=1.1;CM-VER=3.1;
Wed Mar 24 10:13:33 2021	Warning (5)	Dynamic Range Window violation
Wed Mar 24 10:13:33 2021	Warning (5)	RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=08:36:c9:40:c3:d0;CMTS-MAC=00:17:10:86:bd:cb;CM-QOS=1.1;CM-VER=3.1;
Wed Mar 24 10:13:33 2021	Critical (3)	Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:40:c3:d0;CMTS-MAC=00:17:10:86:bd:cb;CM-QOS=1.1;CM-VER=3.1;
Wed Mar 24 10:13:27 2021	Warning (5)	Dynamic Range Window violation
Wed Mar 24 10:13:27 2021	Warning (5)	RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=08:36:c9:40:c3:d0;CMTS-MAC=00:17:10:86:bd:cb;CM-QOS=1.1;CM-VER=3.1;

[Telcontarr]

I'm getting really tired of dealing with problems with Netgear equipment. Is there no support to tell me what's going wrong? 

[FURRYe38]

Seeing lots of uncorrectables on the status table. Seems that the mofem can't get a good signal or having problems with the signal on the line. 

What Version of FW is loaded on the modem? 

[Telcontarr]

During the last Spectrum technician visit, they said the signal from their tap to the house to the modem itself was "perfect". They technician saw no reported failures or outages in their signal over the last 7 days, despite me experiencing these disconnections frequently over the course of a a day for a week or more.

Current Firmware is  V1.02.01, but Spectrum has not updated the approved firmware.

Is there something else I could be missing? A power supply issue to the modem?

[FURRYe38]

Good luck in getting Spectrum to update modem FW. I believe there ones that don't for user owned modems. Can do a search here in the forums regarding Spectrum and user owned modems. 

Can try a different power supply to see. Ensure its the same voltage and amps as on the NG supply that came with the modem. 

[Telcontarr]

Does that mean the FW is likely to be the cause of the issue?

[FURRYe38]

Possible.