Re: Please take a look at CM-1000 modem signals & error log and advise. Thanks - Xfinity Help and Support Forums

CircaRhythm · ‎03-22-2020

Would you mind looking at mine and seeing if there is any problems? I've been having constant disconnects every few hours for the first time ever for about a week straight so far(been with Comcast for 2 years) and I'm not sure if the connection is throttling because of a wave of new customers because of their new 60 Day Free Unlimited Data Cable Internet deal or what. Talked to a representative twice and haven't figured it out because they say the connection seems healthy from their side. I have a tech scheduled but I don't want to pay if there's no problem and them blaming it on the modem and I'm also scared of contracting Coronavirus.

Here are my modem details on the Netgear CM1000. Thanks

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

Procedure	Status	Comment
Acquire Downstream Channel	555000000 Hz	Locked
Connectivity State	OK	Operational
Boot State	OK	Operational
Security	Enable	BPI+
IP Provisioning Mode	Honor MDD	IPv6 only

<tabindex=-1>Downstream Bonded Channels</tabindex=-1>

Channel	Lock Status	Modulation	Channel ID	Frequency	Power	SNR / MER	Unerrored Codewords	Correctable Codewords	Uncorrectable Codewords
1	Locked	QAM256	20	555000000 Hz	8.1 dBmV	40.2 dB	62881475	1	0
2	Locked	QAM256	17	537000000 Hz	8.2 dBmV	40.1 dB	61810662	0	0
3	Locked	QAM256	18	543000000 Hz	8.0 dBmV	39.9 dB	61814277	0	0
4	Locked	QAM256	19	549000000 Hz	7.9 dBmV	40.2 dB	61817975	0	0
5	Locked	QAM256	21	561000000 Hz	8.5 dBmV	40.1 dB	61821547	0	0
6	Locked	QAM256	22	567000000 Hz	8.6 dBmV	40.1 dB	61825685	0	0
7	Locked	QAM256	23	573000000 Hz	8.5 dBmV	39.9 dB	61828894	0	0
8	Locked	QAM256	24	579000000 Hz	8.5 dBmV	39.9 dB	61832614	0	0
9	Locked	QAM256	25	585000000 Hz	8.6 dBmV	39.8 dB	61836582	0	0
10	Locked	QAM256	26	591000000 Hz	8.8 dBmV	39.8 dB	61840052	1	0
11	Locked	QAM256	27	597000000 Hz	8.6 dBmV	39.7 dB	61843538	0	0
12	Locked	QAM256	28	603000000 Hz	8.3 dBmV	39.8 dB	61847548	0	0
13	Locked	QAM256	29	609000000 Hz	7.8 dBmV	39.5 dB	61851281	1	0
14	Locked	QAM256	30	615000000 Hz	7.9 dBmV	39.5 dB	61855048	0	0
15	Locked	QAM256	31	621000000 Hz	8.2 dBmV	39.5 dB	61858951	0	0
16	Locked	QAM256	32	627000000 Hz	8.2 dBmV	39.6 dB	61862338	0	0
17	Locked	QAM256	33	633000000 Hz	8.0 dBmV	39.7 dB	61866274	0	0
18	Locked	QAM256	34	639000000 Hz	7.8 dBmV	39.6 dB	61870171	0	0
19	Locked	QAM256	35	645000000 Hz	8.3 dBmV	39.6 dB	61873696	0	0
20	Locked	QAM256	36	651000000 Hz	8.2 dBmV	39.2 dB	61877401	0	0
21	Locked	QAM256	37	657000000 Hz	8.2 dBmV	39.4 dB	61880850	0	0
22	Locked	QAM256	38	663000000 Hz	7.9 dBmV	39.4 dB	61884705	0	0
23	Locked	QAM256	39	669000000 Hz	8.2 dBmV	39.4 dB	61888459	0	0
24	Locked	QAM256	40	675000000 Hz	8.5 dBmV	39.3 dB	61892551	0	0
25	Locked	QAM256	41	681000000 Hz	9.0 dBmV	39.4 dB	61895669	0	0
26	Locked	QAM256	42	687000000 Hz	9.2 dBmV	39.5 dB	61899653	0	0
27	Locked	QAM256	43	693000000 Hz	8.8 dBmV	39.3 dB	61903726	0	0
28	Locked	QAM256	44	699000000 Hz	8.9 dBmV	39.3 dB	61906954	0	0
29	Locked	QAM256	45	705000000 Hz	9.3 dBmV	39.5 dB	61909118	0	0
30	Locked	QAM256	46	711000000 Hz	9.6 dBmV	39.1 dB	61910505	0	0
31	Locked	QAM256	47	717000000 Hz	9.3 dBmV	39.5 dB	61911278	0	0
32	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0	0

<tabindex=-1>Upstream Bonded Channels</tabindex=-1>

Channel	Lock Status	Modulation	Channel ID	Frequency	Power
1	Locked	ATDMA	33	36500000 Hz	47.8 dBmV
2	Locked	ATDMA	34	30100000 Hz	48.3 dBmV
3	Locked	ATDMA	35	23700000 Hz	46.8 dBmV
4	Locked	ATDMA	36	17300000 Hz	45.8 dBmV
5	Not Locked	Unknown	0	0 Hz	0.0 dBmV
6	Not Locked	Unknown	0	0 Hz	0.0 dBmV
7	Not Locked	Unknown	0	0 Hz	0.0 dBmV
8	Not Locked	Unknown	0	0 Hz	0.0 dBmV

<tabindex=-1>Downstream OFDM Channels</tabindex=-1>

Channel	Lock Status	Modulation / Profile ID	Channel ID	Frequency	Power	SNR / MER	Active Subcarrier Number Range	Unerrored Codewords	Correctable Codewords	Uncorrectable Codewords
1	Locked	0, 1, 2, 3	48	805000000 Hz	5.6 dBmV	36.3 dB	1168 ~ 2927	13036814	12620834	0
2	Not Locked	0	0	0 Hz	5.9 dBmV	0.0 dB	0 ~ 4095	0	0	0

<tabindex=-1>Upstream OFDMA Channels</tabindex=-1>

Channel	Lock Status	Modulation / Profile ID	Channel ID	Frequency	Power
1	Not Locked	Unknown	0	0 Hz	0 dBmV
2	Not Locked	Unknown	0	0 Hz	0 dBmV

CircaRhythm · ‎03-22-2020

Here are my event logs @EG

2020-03-22, 11:43:53	Notice (6)	DS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1 2 3.;CM-MAC=cc:40:d0:25:65:30;CMTS-MAC=00:01:5c:63:aa:4a;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Notice (6)	Honoring MDD; IP provisioning mode = IPv6
Time Not Established	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=cc:40:d0:25:65:30;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=cc:40:d0:25:65:30;CMTS-MAC=00:01:5c:63:aa:4a;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=cc:40:d0:25:65:30;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=cc:40:d0:25:65:30;CMTS-MAC=00:01:5c:63:aa:4a;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=cc:40:d0:25:65:30;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=cc:40:d0:25:65:30;CMTS-MAC=00:01:5c:63:aa:4a;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=cc:40:d0:25:65:30;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=cc:40:d0:25:65:30;CMTS-MAC=00:01:5c:63:aa:4a;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=cc:40:d0:25:65:30;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=cc:40:d0:25:65:30;CMTS-MAC=00:01:5c:63:aa:4a;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=cc:40:d0:25:65:30;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2020-03-21, 11:50:27	Critical (3)	Resetting the cable modem due to docsDevResetNow
Time Not Established	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=cc:40:d0:25:65:30;CMTS-MAC=00:01:5c:63:aa:4a;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=cc:40:d0:25:65:30;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2020-03-21, 11:21:24	Critical (3)	Resetting the cable modem due to docsDevResetNow
Time Not Established	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=cc:40:d0:25:65:30;CMTS-MAC=00:01:5c:63:aa:4a;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=cc:40:d0:25:65:30;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=cc:40:d0:25:65:30;CMTS-MAC=00:01:5c:63:aa:4a;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=cc:40:d0:25:65:30;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=cc:40:d0:25:65:30;CMTS-MAC=00:01:5c:63:aa:4a;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=cc:40:d0:25:65:30;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=cc:40:d0:25:65:30;CMTS-MAC=00:01:5c:63:aa:4a;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=cc:40:d0:25:65:30;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=cc:40:d0:25:65:30;CMTS-MAC=00:01:5c:63:aa:4a;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=cc:40:d0:25:65:30;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=cc:40:d0:25:65:30;CMTS-MAC=00:01:5c:63:aa:4a;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=cc:40:d0:25:65:30;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=cc:40:d0:25:65:30;CMTS-MAC=00:01:5c:63:aa:4a;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=cc:40:d0:25:65:30;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=cc:40:d0:25:65:30;CMTS-MAC=00:01:5c:63:aa:4a;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=cc:40:d0:25:65:30;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=cc:40:d0:25:65:30;CMTS-MAC=00:01:5c:63:aa:4a;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=cc:40:d0:25:65:30;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=cc:40:d0:25:65:30;CMTS-MAC=00:01:5c:63:aa:4a;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=cc:40:d0:25:65:30;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=cc:40:d0:25:65:30;CMTS-MAC=00:01:5c:63:aa:4a;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=cc:40:d0:25:65:30;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2020-03-03, 01:24:11	Critical (3)	Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=cc:40:d0:25:65:30;CMTS-MAC=00:01:5c:63:aa:4a;CM-QOS=1.1;CM-VER=3.1;

EG · ‎03-22-2020

The upstream power is a bit on the high side (especially on channel number 2) and it may be intermittently fluctuating even higher to out of spec levels. That can cause random disconnects, spontaneous re-booting of the modem, speed, packet loss, and latency problems.

In a self troubleshooting effort to try to obtain better connectivity / more wiggle room, check to see if there are there any excess/unneeded coax cable splitters in the line leading to the modem that can be eliminated/re-configured. Any splitters that remain should be high quality and cable rated for 5-1002 MHz, bi-directional, and no gold colored garbage types like GE, RadioShack, RCA, Philips, Leviton, Magnavox, and Rocketfish from big box stores like Home Depot, Lowes, Target, Wal-Mart etc. Splitters should be swapped with known to be good / new ones to test

If there aren't any unneeded splitters that can be eliminated and if your coax wiring setup can't be reconfigured so that there is a single two way splitter connected directly off of the drop from the street/pole with one port feeding the modem and the other port feeding the rest of the house/equipment with additional splits as needed, and you've checked all the wiring and fittings for integrity and tightness and refresh them by taking them apart then check for and clean off any corrosion / oxidation on the center wire and put them back together again, then perhaps it's best to book a tech visit to investigate and correct.

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I am a Customer Expert volunteering my time to help other customers here in the Forums.
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CircaRhythm · ‎03-22-2020

Thank you.

Am I able to call and tell them to put less power into Upstream channel 2? Or does a technician have to come and do that

And do you have any recommendations on a Coax Cable brand?

EG · ‎03-22-2020

@CircaRhythm wrote:

Thank you.

Am I able to call and tell them to put less power into Upstream channel 2? Or does a technician have to come and do that

No. It doesn't work like that. It takes a *boots on the ground* physical intervention.

I am not a Comcast Employee.
I am a Customer Expert volunteering my time to help other customers here in the Forums.
We ask that you post publicly so people with similar questions may benefit from the conversation.
Was your question answered? Mark the post as Best Answer!