CM700 dropping internet, xfinity claims cable OK

[yekiMikey]

My CM700 is dropping internet regularly and a reboot of the modem generally recovers from the problem the quickest. The following is a log snippet that is representative of the whole event log:

Time Not Established	Critical (3)	No Ranging Response received - T3 time-out
Jan 23 2023 10:09:08	Warning (5)	MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1
Jan 23 2023 11:29:22	Critical (3)	No Ranging Response received - T3 time-out
Jan 25 2023 09:22:00	Warning (5)	MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1
Time Not Established	Critical (3)	No Ranging Response received - T3 time-out
Jan 25 2023 10:30:06	Warning (5)	MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1
Jan 26 2023 07:55:20	Critical (3)	No Ranging Response received - T3 time-out
Jan 26 2023 13:56:33	Warning (5)	MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1
Time Not Established	Critical (3)	No Ranging Response received - T3 time-out
Jan 26 2023 21:08:07	Warning (5)	MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1
Jan 27 2023 04:42:28	Critical (3)	No Ranging Response received - T3 time-out
Jan 27 2023 10:59:38	Warning (5)	MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1
Jan 28 2023 13:44:42	Critical (3)	No Ranging Response received - T3 time-out
Jan 29 2023 23:01:32	Warning (5)	MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1
Time Not Established	Critical (3)	No Ranging Response received - T3 time-out
Jan 30 2023 01:01:30	Warning (5)	MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1
Jan 30 2023 01:01:35	Critical (3)	No Ranging Response received - T3 time-out
Jan 30 2023 09:13:02	Warning (5)	MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1
Time Not Established	Critical (3)	No Ranging Response received - T3 time-out
Jan 30 2023 09:27:10	Warning (5)	MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1
Time Not Established	Critical (3)	No Ranging Response received - T3 time-out
Jan 30 2023 09:53:19	Warning (5)	MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1

I had xfinity come out to verify the lines and their representative said there were "loose and old" connections and then he "fixed them" but I continued to have issues. I do not have any splitters and my line is as simple as it gets. Any chance this could be a modem hardware issue? Any recommendations on steps moving forward? Is the most likely scenario that the xfinity guy is simply wrong?

[FURRYe38]

You have Criticals and Warnings that the ISP needs to review and resolve from there side. 

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...

Be sure your using a good quality LAN cable between the modem and router. CAT6 is recommended. 
What is the brand and model of the host wifi router connected to the modem?

Have the ISP check the signal and line quality UP to the modem. Be sure the ISP provisions the modem correctly.
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://kb.netgear.com/24311/Power-level-guidelines-for-a-NETGEAR-cable-modem-router
https://www.duckware.com/tech/solving-intermittent-cable-modem-issues.html

[yekiMikey]

I am using a tp-link deco ac1200 router. Xfinity claims the cables on their side are OK. 

<tabindex=-1>Startup Procedure</tabindex=-1>

Procedure Status Comment Acquire Downstream Channel 411000000 Hz Locked Connectivity State Ok Operational Boot State Ok Operational Security Enabled BPI+ IP Provisioning Mode Honor MDD honorMdd(4)

Downstream Bonded Channels

Channel Lock Status Modulation Channel ID Frequency Power SNR Correctables UnCorrectables 1 Locked QAM 256 1 387000000 Hz 3.0 dBmV 37.3 dB 0 0 2 Locked QAM 256 2 393000000 Hz 3.0 dBmV 37.3 dB 0 0 3 Locked QAM 256 3 399000000 Hz 3.0 dBmV 37.3 dB 0 0 4 Locked QAM 256 4 405000000 Hz 3.0 dBmV 36.6 dB 0 0 5 Locked QAM 256 5 411000000 Hz 3.2 dBmV 36.3 dB 0 0 6 Locked QAM 256 6 417000000 Hz 3.2 dBmV 36.6 dB 0 0 7 Locked QAM 256 7 423000000 Hz 3.0 dBmV 37.3 dB 0 0 8 Locked QAM 256 8 429000000 Hz 3.0 dBmV 37.3 dB 0 0 9 Locked QAM 256 9 435000000 Hz 3.0 dBmV 36.6 dB 0 0 10 Locked QAM 256 10 441000000 Hz 3.0 dBmV 37.3 dB 0 0 11 Locked QAM 256 11 447000000 Hz 3.0 dBmV 37.3 dB 0 0 12 Locked QAM 256 12 453000000 Hz 3.0 dBmV 36.6 dB 0 1 13 Locked QAM 256 13 459000000 Hz 3.2 dBmV 36.6 dB 0 0 14 Locked QAM 256 14 465000000 Hz 3.0 dBmV 36.6 dB 23 0 15 Locked QAM 256 15 471000000 Hz 3.2 dBmV 37.3 dB 0 0 16 Locked QAM 256 16 477000000 Hz 3.4 dBmV 37.3 dB 7 0 17 Locked QAM 256 17 483000000 Hz 3.5 dBmV 37.3 dB 0 0 18 Locked QAM 256 18 489000000 Hz 3.7 dBmV 36.3 dB 4 0 19 Locked QAM 256 19 495000000 Hz 3.7 dBmV 37.3 dB 7 0 20 Locked QAM 256 20 507000000 Hz 4.0 dBmV 37.3 dB 0 0 21 Locked QAM 256 21 513000000 Hz 3.9 dBmV 37.6 dB 0 0 22 Locked QAM 256 22 519000000 Hz 4.0 dBmV 37.6 dB 0 0 23 Locked QAM 256 23 525000000 Hz 4.1 dBmV 37.3 dB 0 0 24 Locked QAM 256 24 531000000 Hz 4.5 dBmV 37.3 dB 16 0 25 Locked QAM 256 25 537000000 Hz 4.4 dBmV 37.3 dB 7 0 26 Locked QAM 256 26 543000000 Hz 4.4 dBmV 37.3 dB 1725 0 27 Locked QAM 256 27 555000000 Hz 4.5 dBmV 36.9 dB 97 625 28 Locked QAM 256 28 561000000 Hz 4.5 dBmV 36.9 dB 10 0 29 Locked QAM 256 29 567000000 Hz 4.8 dBmV 37.3 dB 18 0 30 Locked QAM 256 30 573000000 Hz 4.9 dBmV 37.6 dB 0 0 31 Locked QAM 256 31 579000000 Hz 4.9 dBmV 37.6 dB 0 0 32 Locked QAM 256 32 585000000 Hz 5.0 dBmV 37.9 dB 0 0

Upstream Bonded Channels

Channel Lock Status US Channel Type Channel ID Symbol Rate Frequency Power 1 Locked ATDMA 8 5120 Ksym/sec 16400000 Hz 44.5 dBmV 2 Locked ATDMA 7 5120 Ksym/sec 22800000 Hz 44.8 dBmV 3 Locked ATDMA 6 5120 Ksym/sec 29200000 Hz 44.8 dBmV 4 Locked ATDMA 5 5120 Ksym/sec 35600000 Hz 44.5 dBmV 5 Locked ATDMA 10 1280 Ksym/sec 39600000 Hz 41.5 dBmV 6 Not Locked N/A Unknown 0 Ksym/sec 0 Hz 0.0 dBmV 7 Not Locked N/A Unknown 0 Ksym/sec 0 Hz 0.0 dBmV 8 Not Locked N/A Unknown 0 Ksym/sec 0 Hz 0.0 dBmV

[yekiMikey]

I also found my cm700 on the "bad modems" page, I'm wondering if it could be that...

[FURRYe38]

Well power levels are good. There a a few Correct and Un-correctables that could be/should be zeros, however don't think those would be a real cause. 

Ya the CM700 is a Intel Puma based chipset modem and was on a list that came from DSLReports site. 
You could try a different modem, the CM1000, 1100 and 1200 are Broadcom based modems are not effected by the Intel vulnerability. Might try a different modem to see if the problem follows.

[yekiMikey]

Sounds good, I will try that, thank you for the assistance!

[FURRYe38]

👍