CM1200 - Only One Locked Upstream Bonded Channel

[eXgU2q3NDNT3RTf]

I have a CM1200 paired with Spectrum service running firmware version 1.02.01.

The modem reports only one locked upstream bonded channel.  I occasionally experience (seemingly random) disconnects, which is a problem during the work from home era.

A Spectrum tech spent a half-day at my location and came to the conclusion that the problem is with the modem.  He says the Spectrum-issued modem locks all four upstream bonded channels, whereas my modem locks only one.

I assume the service provider - hardware provider finger pointing is common.   How can I assess if I have a bad modem as per the Spectrum tech?

Startup Procedure

Procedure Status Comment Acquire Downstream Channel 765000000 Hz Locked Connectivity State OK Operational Boot State OK Operational Security Enabled BPI+ IP Provisioning Mode Honor MDD honorMdd(4)

Downstream Bonded Channels (Partial Service)

Channel Lock Status Modulation Channel ID Frequency Power SNR Correctables Uncorrectables 1 Locked QAM256 32 765000000 Hz 4.3 dBmV 41.7 dB 0 0 2 Locked QAM256 1 579000000 Hz 2.1 dBmV 40.3 dB 0 0 3 Locked QAM256 2 585000000 Hz 2 dBmV 40.4 dB 0 0 4 Locked QAM256 3 591000000 Hz 2 dBmV 40.4 dB 0 0 5 Locked QAM256 4 597000000 Hz 2.2 dBmV 40.4 dB 0 0 6 Locked QAM256 5 603000000 Hz 2.2 dBmV 40.5 dB 0 0 7 Locked QAM256 6 609000000 Hz 2.2 dBmV 40.4 dB 0 0 8 Locked QAM256 7 615000000 Hz 2.3 dBmV 40.6 dB 0 0 9 Locked QAM256 8 621000000 Hz 2.5 dBmV 40.6 dB 0 0 10 Locked QAM256 9 627000000 Hz 2 dBmV 40.4 dB 0 0 11 Locked QAM256 10 633000000 Hz 2.2 dBmV 40.3 dB 0 0 12 Locked QAM256 11 639000000 Hz 2.6 dBmV 40.6 dB 0 0 13 Locked QAM256 12 645000000 Hz 2.9 dBmV 40.7 dB 0 0 14 Locked QAM256 13 651000000 Hz 2.8 dBmV 40.7 dB 0 0 15 Locked QAM256 14 657000000 Hz 2.5 dBmV 40.6 dB 0 0 16 Locked QAM256 15 663000000 Hz 2.9 dBmV 40.9 dB 0 0 17 Locked QAM256 16 669000000 Hz 3.1 dBmV 41 dB 0 0 18 Locked QAM256 17 675000000 Hz 3.3 dBmV 40.5 dB 0 0 19 Locked QAM256 18 681000000 Hz 3.2 dBmV 41 dB 0 0 20 Locked QAM256 19 687000000 Hz 3.4 dBmV 41 dB 0 0 21 Locked QAM256 20 693000000 Hz 3.3 dBmV 40.9 dB 0 0 22 Locked QAM256 21 699000000 Hz 3.5 dBmV 41.1 dB 0 0 23 Locked QAM256 22 705000000 Hz 3.8 dBmV 41.1 dB 0 0 24 Locked QAM256 23 711000000 Hz 3.9 dBmV 41.2 dB 0 0 25 Locked QAM256 24 717000000 Hz 3.7 dBmV 41.1 dB 0 0 26 Locked QAM256 25 723000000 Hz 3.8 dBmV 41.2 dB 0 0 27 Locked QAM256 26 729000000 Hz 4 dBmV 41.4 dB 0 0 28 Locked QAM256 27 735000000 Hz 4.4 dBmV 41.7 dB 0 0 29 Locked QAM256 28 741000000 Hz 4.1 dBmV 41.5 dB 0 0 30 Locked QAM256 29 747000000 Hz 4 dBmV 41.4 dB 0 0 31 Locked QAM256 30 753000000 Hz 4.2 dBmV 41.5 dB 0 0 32 Locked QAM256 31 759000000 Hz 4.5 dBmV 41.8 dB 0 0

Upstream Bonded Channels (Partial Service)

Channel Lock Status US Channel Type Channel ID Symbol Rate Frequency Power 1 Locked ATDMA 1 5120 Ksym/sec 17600000 Hz 47.3 dBmV 2 Not Locked Unknown 2 0 Ksym/sec 17600000 Hz 0.0 dBmV 3 Not Locked Unknown 3 0 Ksym/sec 24000000 Hz 0.0 dBmV 4 Not Locked Unknown 4 0 Ksym/sec 30400000 Hz 0.0 dBmV 5 Not Locked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV 6 Not Locked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV 7 Not Locked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV 8 Not Locked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV

Downstream OFDM Channels

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 ,2 159 272000000 Hz 2.1 dBmV 41.4 dB 628 ~ 3467 23932562 374156 0 2 Not Locked 0 0 0 Hz 0 dBmV 0.0 dB 0 ~ 4095 0 0 0

Upstream OFDMA Channels

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

[FURRYe38]

Well your on latest FW for Spectrum:

https://kb.netgear.com/000036375/What-s-the-latest-firmware-version-of-my-NETGEAR-cable-modem-or-mod...

Was the following checked? 

Be sure there are no coax cable line splitters in the between the modem and ISP service box. 
https://community.netgear.com/t5/Cable-Modems-Routers/General-info-and-Troubleshooting-for-Cable-Mod...
https://highspeed.tips/docsis-events/

[eXgU2q3NDNT3RTf]

Yes sir.  There are no line splitters between the modem and ISP service box.

In addition:

- Tech replaced my RG-6 with his own.

- Rebooted CM1200.

- Factory reset CM1200.

My event logs are filled with:

- Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=00:00:00:00:00:00;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;

- Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=00:00:00:00:00:00;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;

* MAC addresses redacted.

I doubt the modem is bad and welcome any additional options to explore.

[FURRYe38]

Check with NG support to see if there are any options available to you. Ask about an RMA. 

[eXgU2q3NDNT3RTf]

I started the process to explore RMA options with NG, and was asked to pay for support in order to proceed since I am outside of 90-day window.   I may try again, or keep exploring options online.  This community deserves kudos however.

[Gryff36]

I had the same issue just last week and I can say it was not the equipment as I bought the CM1200 last month to replace an older nighthawk modem/router combo.  This entire time I thought the threshold of 52+ DBs was ok up to 57 DBs, but come to find out that that is the analog standard for Spectrum as explained by the technician Supervisor.  As soon as he pulled my modem's information he saw three upstream channels locked at 51.3, 51.0, and 51.8.  He said that at 52 DB on an all digital system is the threshold.  I live in NC where I guess it is all digital where I live.  The first tech that came out adjusted my upstream to 50 DBs readings, but then without being told after he left, the regional maintenance crew changed the levels for the entire area which then made my DBs go back to the readings I just mentioned before.  Then the Tech Supervisor called and pulled information from my modem after an entire day of complaining to tech support on the phone.  Simple fix too.  Your splitter on the outside of the home where the coax cable goes into the home has like 5 different connection spaces on it.  Two will be for input and output.  The other three will have different measurements for reducing the DBs on the line as I was explained.  I would suggest your tech work with the splitter as they know more about configuring the splitter to work perfectly.  All the tech supervisor did, was increase the measured reduction connection from -3 DB to -7 DB.  Now my three upstream channels are locked solid with a 47.3, 48.0, and 47.7.  A good cushion for staying under the maximum.  I subscribe for 400 Mb/sec download and 20Mb/sec upload and am reading 480 Mb/sec download and 80 Mb/sec upload tested with speedtest.net to AT&T in Mexico City, Mexico (I decided to test out of network to ensure that it is not just an in Spectrum ploy to tell me my speed is fast in the network).

Oh and believe me I thought it was a faulty modem mixed with the Orbi Mesh Router. 

Hope all is good with you all and your systems are doing well.  

[FURRYe38]

Here were mine is with my ISP:

Upstream Bonded Channels

Channel Lock Status US Channel Type Channel ID Symbol Rate Frequency Power 1 Locked ATDMA 1 5120 Ksym/sec 36000000 Hz 40.5 dBmV 2 Locked ATDMA 2 5120 Ksym/sec 29000000 Hz 39 dBmV 3 Locked ATDMA 5 5120 Ksym/sec 22000000 Hz 39.3 dBmV 4 Locked ATDMA 6 2560 Ksym/sec 16000000 Hz 38 dBmV