CM2000 Modem: blinking downstream light

[HGinDC]

Hello. I am using a Nighthawk CM2000 router (which, BTW, is not a listed model for the model dropdown) connected to a Nighthawk AX4 router. Periodically the downstream light on the modem starts blinking white ("modem is scanning for a downstream channel"), and the only way to get it to stop blinking and stay on steadily is to restart the modem. The thing is, though, even while the light is blinking the WiFi connection seems to be unaffected. In fact it is blinking now while I'm online here and typing this message. I even ran a Speedtest.net test while the light was blinking and got some of the fastest speeds I have so far obtained with this router (see below). My question is, can I safely ignore this blinking light, or should I reboot the modem every time it happens? Thanks all!

--Howard

[FURRYe38]

Please post a copy and paste of the modems connection status page.
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. 
Be sure to power OFF the modem for 1 minute them back ON.
https://community.netgear.com/t5/Cable-Modems-Routers/General-info-and-Troubleshooting-for-Cable-Mod...

[HGinDC]

Thank you for the response. Below is a copy of the "modem event log." Is this the info you requested? I have been often in touch with RCN and the modem has been "reprovisioned" several times. Also, I have had (and paid for) three service calls. This first time the tech replaced the connectors at the ends of the cable, and removed one splitter her found in the line. The subsequent visits found the signal to be within spec, and the tech stated that since I had my own modem that was all they could do since they did not support customer-owned modems.

Tue Jul 06 06:09:00 2021 (Error (4)) DHCP RENEW WARNING - Field invalid in response v4 option;CM-MAC=08:36:c9:9f:5e:a8;CMTS-MAC=00:af:1f:1f:85:5e;CM-QOS=1.1;CM-VER=3.1;
Mon Jul 05 01:45:51 2021 (Notice (6)) CM-STATUS message sent. Event Type Code: 22; Chan ID: 159; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=08:36:c9:9f:5e:a8;CMTS-MAC=00:af:1f:1f:85:5e;CM-QOS=1.1;CM-VER=3.1;
Mon Jul 05 01:45:26 2021 (Notice (6)) CM-STATUS message sent. Event Type Code: 20; Chan ID: 159; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=08:36:c9:9f:5e:a8;CMTS-MAC=00:af:1f:1f:85:5e;CM-QOS=1.1;CM-VER=3.1;
Mon Jul 05 01:21:01 2021 (Notice (6)) CM-STATUS message sent. Event Type Code: 22; Chan ID: 159; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=08:36:c9:9f:5e:a8;CMTS-MAC=00:af:1f:1f:85:5e;CM-QOS=1.1;CM-VER=3.1;
Mon Jul 05 01:20:36 2021 (Notice (6)) CM-STATUS message sent. Event Type Code: 20; Chan ID: 159; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=08:36:c9:9f:5e:a8;CMTS-MAC=00:af:1f:1f:85:5e;CM-QOS=1.1;CM-VER=3.1;
Fri Jul 02 18:09:00 2021 (Error (4)) DHCP RENEW WARNING - Field invalid in response v4 option;CM-MAC=08:36:c9:9f:5e:a8;CMTS-MAC=00:af:1f:1f:85:5e;CM-QOS=1.1;CM-VER=3.1;
Fri Jul 02 09:17:21 2021 (Critical (3)) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:9f:5e:a8;CMTS-MAC=00:af:1f:1f:85:5e;CM-QOS=1.1;CM-VER=3.1;
Tue Jun 29 06:09:00 2021 (Error (4)) DHCP RENEW WARNING - Field invalid in response v4 option;CM-MAC=08:36:c9:9f:5e:a8;CMTS-MAC=00:af:1f:1f:85:5e;CM-QOS=1.1;CM-VER=3.1;
Sat Jun 26 23:09:53 2021 (Critical (3)) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:9f:5e:a8;CMTS-MAC=00:af:1f:1f:85:5e;CM-QOS=1.1;CM-VER=3.1;
Fri Jun 25 18:09:08 2021 (Warning (5)) REG-RSP-MP Mismatch Between Calculated Value for P1.6hi Compared to CCAP Provided Value;CM-MAC=08:36:c9:9f:5e:a8;CMTS-MAC=00:af:1f:1f:85:5e;CM-QOS=1.1;CM-VER=3.1;
Fri Jun 25 18:09:06 2021 (Notice (6)) DS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1 2 3.;CM-MAC=08:36:c9:9f:5e:a8;CMTS-MAC=00:af:1f:1f:85:5e;CM-QOS=1.1;CM-VER=3.1;
Fri Jun 25 18:09:01 2021 (Notice (6)) TLV-11 - unrecognized OID;CM-MAC=08:36:c9:9f:5e:a8;CMTS-MAC=00:af:1f:1f:85:5e;CM-QOS=1.1;CM-VER=3.1;
Fri Jun 25 18:09:01 2021 (Error (4)) Missing BP Configuration Setting TLV Type: 17.9;CM-MAC=08:36:c9:9f:5e:a8;CMTS-MAC=00:af:1f:1f:85:5e;CM-QOS=1.1;CM-VER=3.1;
Fri Jun 25 18:09:01 2021 (Error (4)) Missing BP Configuration Setting TLV Type: 17.8;CM-MAC=08:36:c9:9f:5e:a8;CMTS-MAC=00:af:1f:1f:85:5e;CM-QOS=1.1;CM-VER=3.1;
Fri Jun 25 18:09:01 2021 (Error (4)) Missing BP Configuration Setting TLV Type: 17.7;CM-MAC=08:36:c9:9f:5e:a8;CMTS-MAC=00:af:1f:1f:85:5e;CM-QOS=1.1;CM-VER=3.1;
Fri Jun 25 18:09:01 2021 (Error (4)) Missing BP Configuration Setting TLV Type: 17.6;CM-MAC=08:36:c9:9f:5e:a8;CMTS-MAC=00:af:1f:1f:85:5e;CM-QOS=1.1;CM-VER=3.1;
Fri Jun 25 18:09:01 2021 (Error (4)) Missing BP Configuration Setting TLV Type: 17.5;CM-MAC=08:36:c9:9f:5e:a8;CMTS-MAC=00:af:1f:1f:85:5e;CM-QOS=1.1;CM-VER=3.1;
Fri Jun 25 18:09:01 2021 (Error (4)) Missing BP Configuration Setting TLV Type: 17.4;CM-MAC=08:36:c9:9f:5e:a8;CMTS-MAC=00:af:1f:1f:85:5e;CM-QOS=1.1;CM-VER=3.1;
Fri Jun 25 18:09:01 2021 (Error (4)) Missing BP Configuration Setting TLV Type: 17.3;CM-MAC=08:36:c9:9f:5e:a8;CMTS-MAC=00:af:1f:1f:85:5e;CM-QOS=1.1;CM-VER=3.1;
Fri Jun 25 18:09:01 2021 (Error (4)) Missing BP Configuration Setting TLV Type: 17.2;CM-MAC=08:36:c9:9f:5e:a8;CMTS-MAC=00:af:1f:1f:85:5e;CM-QOS=1.1;CM-VER=3.1;
Fri Jun 25 18:09:01 2021 (Error (4)) Missing BP Configuration Setting TLV Type: 17.1;CM-MAC=08:36:c9:9f:5e:a8;CMTS-MAC=00:af:1f:1f:85:5e;CM-QOS=1.1;CM-VER=3.1;
Fri Jun 25 18:09:01 2021 (Warning (5)) DHCP WARNING - Non-critical field invalid in response ;CM-MAC=08:36:c9:9f:5e:a8;CMTS-MAC=00:af:1f:1f:85:5e;CM-QOS=1.1;CM-VER=3.1;
Time Not Established (Notice (6)) Honoring MDD; IP provisioning mode = IPv4
Time Not Established (Critical (3)) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=08:36:c9:9f:5e:a8;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
Fri Jun 25 09:41:52 2021 (Error (4)) DHCP RENEW WARNING - Field invalid in response v4 option;CM-MAC=08:36:c9:9f:5e:a8;CMTS-MAC=00:af:1f:1f:85:5e;CM-QOS=1.1;CM-VER=3.1;
Thu Jun 24 17:50:57 2021 (Notice (6)) CM-STATUS message sent. Event Type Code: 22; Chan ID: 159; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=08:36:c9:9f:5e:a8;CMTS-MAC=00:af:1f:1f:85:5e;CM-QOS=1.1;CM-VER=3.1;
Thu Jun 24 17:50:32 2021 (Notice (6)) CM-STATUS message sent. Event Type Code: 20; Chan ID: 159; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=08:36:c9:9f:5e:a8;CMTS-MAC=00:af:1f:1f:85:5e;CM-QOS=1.1;CM-VER=3.1;
Thu Jun 24 17:50:24 2021 (Notice (6)) CM-STATUS message sent. Event Type Code: 22; Chan ID: 159; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=08:36:c9:9f:5e:a8;CMTS-MAC=00:af:1f:1f:85:5e;CM-QOS=1.1;CM-VER=3.1;
Thu Jun 24 17:49:39 2021 (Notice (6)) CM-STATUS message sent. Event Type Code: 20; Chan ID: 159; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=08:36:c9:9f:5e:a8;CMTS-MAC=00:af:1f:1f:85:5e;CM-QOS=1.1;CM-VER=3.1;
Thu Jun 24 17:48:08 2021 (Notice (6)) CM-STATUS message sent. Event Type Code: 22; Chan ID: 159; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=08:36:c9:9f:5e:a8;CMTS-MAC=00:af:1f:1f:85:5e;CM-QOS=1.1;CM-VER=3.1;
Thu Jun 24 17:45:39 2021 (Notice (6)) CM-STATUS message sent. Event Type Code: 20; Chan ID: 159; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=08:36:c9:9f:5e:a8;CMTS-MAC=00:af:1f:1f:85:5e;CM-QOS=1.1;CM-VER=3.1;
Thu Jun 24 17:44:13 2021 (Notice (6)) CM-STATUS message sent. Event Type Code: 22; Chan ID: 159; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=08:36:c9:9f:5e:a8;CMTS-MAC=00:af:1f:1f:85:5e;CM-QOS=1.1;CM-VER=3.1;
Thu Jun 24 17:43:31 2021 (Notice (6)) CM-STATUS message sent. Event Type Code: 20; Chan ID: 159; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=08:36:c9:9f:5e:a8;CMTS-MAC=00:af:1f:1f:85:5e;CM-QOS=1.1;CM-VER=3.1;
Thu Jun 24 17:19:00 2021 (Notice (6)) CM-STATUS message sent. Event Type Code: 22; Chan ID: 159; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=08:36:c9:9f:5e:a8;CMTS-MAC=00:af:1f:1f:85:5e;CM-QOS=1.1;CM-VER=3.1;
Thu Jun 24 17:18:33 2021 (Notice (6)) CM-STATUS message sent. Event Type Code: 20; Chan ID: 159; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=08:36:c9:9f:5e:a8;CMTS-MAC=00:af:1f:1f:85:5e;CM-QOS=1.1;CM-VER=3.1;
Thu Jun 24 17:16:43 2021 (Notice (6)) CM-STATUS message sent. Event Type Code: 22; Chan ID: 159; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=08:36:c9:9f:5e:a8;CMTS-MAC=00:af:1f:1f:85:5e;CM-QOS=1.1;CM-VER=3.1;
Thu Jun 24 17:15:39 2021 (Notice (6)) CM-STATUS message sent. Event Type Code: 20; Chan ID: 159; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=08:36:c9:9f:5e:a8;CMTS-MAC=00:af:1f:1f:85:5e;CM-QOS=1.1;CM-VER=3.1;
Thu Jun 24 17:14:55 2021 (Notice (6)) CM-STATUS message sent. Event Type Code: 22; Chan ID: 159; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=08:36:c9:9f:5e:a8;CMTS-MAC=00:af:1f:1f:85:5e;CM-QOS=1.1;CM-VER=3.1;
Thu Jun 24 17:14:02 2021 (Notice (6)) CM-STATUS message sent. Event Type Code: 20; Chan ID: 159; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=08:36:c9:9f:5e:a8;CMTS-MAC=00:af:1f:1f:85:5e;CM-QOS=1.1;CM-VER=3.1;
Thu Jun 24 17:13:34 2021 (Notice (6)) CM-STATUS message sent. Event Type Code: 22; Chan ID: 159; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=08:36:c9:9f:5e:a8;CMTS-MAC=00:af:1f:1f:85:5e;CM-QOS=1.1;CM-VER=3.1;

[FURRYe38]

Please post a copy and paste of the modems connection status page.

[HGinDC]

Cable Connection

Frequency start Value This field below allows you to modify the frequency the cable modem start with its scan during initialization and registration. Enter the new start frequency and restart the cable modem for it to take effect. Starting Frequency

Startup Procedure

Procedure Status Comment Acquire Downstream Channel 603000000 Hz Locked Connectivity State OK Operational Boot State OK Operational Security Enabled BPI+

Downstream Bonded Channels

Channel Lock Status Modulation Channel ID Frequency Power SNR Correctables Uncorrectables 1 Locked QAM256 10 603000000 Hz -3.2 dBmV 42.0 dB 0 0 2 Locked QAM256 1 549000000 Hz -0.8 dBmV 43.4 dB 0 0 3 Locked QAM256 2 555000000 Hz -1.7 dBmV 42.7 dB 0 0 4 Locked QAM256 3 561000000 Hz -2.8 dBmV 42.3 dB 0 0 5 Locked QAM256 4 567000000 Hz -2.7 dBmV 42.3 dB 0 0 6 Locked QAM256 5 573000000 Hz -1.1 dBmV 42.4 dB 0 0 7 Locked QAM256 6 579000000 Hz -1.1 dBmV 42.5 dB 0 0 8 Locked QAM256 7 585000000 Hz -1.2 dBmV 42.6 dB 0 0 9 Locked QAM256 8 591000000 Hz -1.9 dBmV 41.1 dB 0 0 10 Locked QAM256 9 597000000 Hz -2.1 dBmV 42.0 dB 0 0 11 Locked QAM256 11 609000000 Hz -3.0 dBmV 41.9 dB 0 0 12 Locked QAM256 12 615000000 Hz -2.3 dBmV 41.9 dB 0 0 13 Locked QAM256 13 621000000 Hz -2.8 dBmV 41.9 dB 0 0 14 Locked QAM256 14 627000000 Hz -4.0 dBmV 41.4 dB 0 0 15 Locked QAM256 15 633000000 Hz -3.3 dBmV 41.3 dB 0 0 16 Locked QAM256 16 639000000 Hz -2.6 dBmV 41.8 dB 0 0 17 Not Locked Unknown 0 0 Hz 0.0 dBmV 0.0 dB 0 0 18 Not Locked Unknown 0 0 Hz 0.0 dBmV 0.0 dB 0 0 19 Not Locked Unknown 0 0 Hz 0.0 dBmV 0.0 dB 0 0 20 Not Locked Unknown 0 0 Hz 0.0 dBmV 0.0 dB 0 0 21 Not Locked Unknown 0 0 Hz 0.0 dBmV 0.0 dB 0 0 22 Not Locked Unknown 0 0 Hz 0.0 dBmV 0.0 dB 0 0 23 Not Locked Unknown 0 0 Hz 0.0 dBmV 0.0 dB 0 0 24 Not Locked Unknown 0 0 Hz 0.0 dBmV 0.0 dB 0 0 25 Not Locked Unknown 0 0 Hz 0.0 dBmV 0.0 dB 0 0 26 Not Locked Unknown 0 0 Hz 0.0 dBmV 0.0 dB 0 0 27 Not Locked Unknown 0 0 Hz 0.0 dBmV 0.0 dB 0 0 28 Not Locked Unknown 0 0 Hz 0.0 dBmV 0.0 dB 0 0 29 Not Locked Unknown 0 0 Hz 0.0 dBmV 0.0 dB 0 0 30 Not Locked Unknown 0 0 Hz 0.0 dBmV 0.0 dB 0 0 31 Not Locked Unknown 0 0 Hz 0.0 dBmV 0.0 dB 0 0 32 Not Locked Unknown 0 0 Hz 0.0 dBmV 0.0 dB 0 0

Upstream Bonded Channels

Channel Lock Status US Channel Type Channel ID Symbol Rate Frequency Power 1 Locked ATDMA 1 5120 36800000 Hz 42.8 dBmV 2 Locked ATDMA 2 5120 30350000 Hz 42.3 dBmV 3 Locked ATDMA 3 5120 23900000 Hz 41.3 dBmV 4 Not Locked Unknown 0 0 0 Hz 0.0 dBmV 5 Not Locked Unknown 0 0 0 Hz 0.0 dBmV 6 Not Locked Unknown 0 0 0 Hz 0.0 dBmV 7 Not Locked Unknown 0 0 0 Hz 0.0 dBmV 8 Not Locked Unknown 0 0 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 ,1 ,2 ,3 159 657000000 Hz -1.7 dBmV 41.2 dB 646 ~ 3449 63583238859 14957734007 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

Extended Upstream Transmit Power

Current System Time:Tue Jul 06 17:29:39 2021System Up Time:10 days 23:21:11

[HGinDC]

I am trying but when I copy the table and paste it here it says the table has HTML errors. It also says it will correct the errors for me, but when I accept and try to repost nothing appears. Can you suggest how I can post the status page?

[FURRYe38]

Usually it should post if you do a direct copy from the web browser and paste in the post. 

Do a screen capture and paste in to Paint and save off to file. Then select Choose File to attach to your post. Inline pictures have to be approved and we have to wait using the photo attach way. 

[FURRYe38]

Who is your ISP? 

What speeds UP and Down do you pay for? 

[HGinDC]

I have RCN. My plan is called "A LA CARTE DATA 1 GIG Modem Service Up to 940 Mbps Internet*

[FURRYe38]

Ok. Seen others post having problems with there modems on RCN. I guess RCN believes using 16 channels instead of 32 for 1Gb services. Something most other ISPs use 32 for 1G services.  I don't see a 4th upstream channel locked in. Usually there is 4 on higher speed tiers. Seems like the modem is having problems here on the up. I would ask the ISP to check the upstream channels. Also maybe that the modem is working ok on the up but just on the fringes of it detecting the up as being out of it's expected spec, however still functional. Though all LEDS should be solid ON. 

[HGinDC]

I think I finally got a decent screen cap of my connection page.

[FURRYe38]

Try this, check the Extended Upstream Transmit Power box and see if this changes anything. If it doesn't un-check the box to disable that. Do a full reboot and test...

[HGinDC]

I checked the "Extended Upstream Transmit Power" box and it didn't make any difference. The Updtream light still blinks from time to time.

[Rcanne]

I also suffer from the same situation on the Nighthawk CM2000 (Blinking downstream light,) and have tried everything that is offered to correct the problem with no results. I restart the modem and typically within days, if not hours the problem is back. The longest it has stayed solid is about a week. Like others have reported the modem seems to be functioning normally; speed is as expected. So, my question is hopefully simple to answer, should I stop concerning myself with the blinking downstream light, and just let it blink? No need to get technical please, just a straight forward "YES" or "NO" would be greatly appreciated.

[FURRYe38]

I would have your ISP check the service line up to the modem. 

Seen others having similar problems with link LEDs blinking and were resolve by the ISP. 

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. 
https://community.netgear.com/t5/Cable-Modems-Routers/General-info-and-Troubleshooting-for-Cable-Mod...
https://www.duckware.com/tech/solving-intermittent-cable-modem-issues.html

---

@HGinDC wrote:

I checked the "Extended Upstream Transmit Power" box and it didn't make any difference. The Updtream light still blinks from time to time.

---

[FURRYe38]

https://community.netgear.com/t5/Cable-Modems-Routers/CM2000-Modem-blinking-downstream-light/m-p/216...

---

@Rcanne wrote:

I also suffer from the same situation on the Nighthawk CM2000 (Blinking downstream light,) and have tried everything that is offered to correct the problem with no results. I restart the modem and typically within days, if not hours the problem is back. The longest it has stayed solid is about a week. Like others have reported the modem seems to be functioning normally; speed is as expected. So, my question is hopefully simple to answer, should I stop concerning myself with the blinking downstream light, and just let it blink? No need to get technical please, just a straight forward "YES" or "NO" would be greatly appreciated.

---

[Rcanne]

Thank you for the feedback, but like I said, I have tried and done it all. You name it I've done it. It has become quite obvious that this particular modem has an issue. I have other rather decent modems and none of them suffered from this problem. So, again is their anyone out there that can answer this rather straight forward question: So, with the blinking downstream light, and that the modem is working just fine, should I stop concerning myself over this issue? YES? or NO?

[FURRYe38]

Up to you. 

Personally, if it's working, leave it. 

Something else to try. Try a different modem and see if same thing happens. Can be telling. 

[Rcanne]

Thank you, that is my thought also, but it is nice to hear an agreement. I did switch back to my previous ASUS, which granted is a little slower, but the issue was not present. When I went back to the Nighthawk the light stayed solid for a week, and then went back to it;s old ways. I'm tired of rebooting it and will just not worry about it anymore. Thanks again for your response.

[FURRYe38]

Keep an eye on things, if you notice something going wrong, get it checked out.