CM700 dropping internet, xfinity claims cable OK

Question

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 · Answer

You have Criticals and Warnings that the ISP needs to review and resolve from there side.&nbsp;
&nbsp;
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-modem-modem-router
&nbsp;
Be sure your using a good quality LAN cable between the modem and router. CAT6 is recommended.&nbsp;What is the brand and model of the host wifi router connected to the modem?
&nbsp;
Have the ISP check the signal and line quality UP to the modem.&nbsp;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-Modems/m-p/1530376#M12853https://kb.netgear.com/24311/Power-level-guidelines-for-a-NETGEAR-cable-modem-routerhttps://www.duckware.com/tech/solving-intermittent-cable-modem-issues.html

yekiMikey · Answer

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 · Answer

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

FURRYe38 · Answer

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.&nbsp;
Ya the CM700 is a Intel Puma based chipset modem and was on a list that came from DSLReports site.&nbsp;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 · Answer

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

Forum Discussion

CM700 dropping internet, xfinity claims cable OK

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