How to read/understand the cable diagnostics on the Nighthawk CAX80.

[highfalutin60]

Hardware Version	1.01
Firmware Version	V2.1.5.2
Cable Firmware Version	V1.02.08

When the connection on the Nighthawk CAX80 changes from good to poor due to the downstream status, how can you determine if it is a cable company issue or could it be a device on your network issue.

I reset my Nighthawk CAX80 after the Xfinity repair guy was here to address the poor downstream connection and sporadic connection issues.  The service person stated he "made some changes/updates at the box" so that I would not be charged the $100 Xfinity service fee.  What those changes are I have no clue.

As I started to add various devices back on to my CAX80, I noticed that the downstream status would change from good to poor sporadically. First, I thought it was my Wyze cameras causing the issue and decided to order 3db Coax Cable Attenuator Pad based on the various test results I was getting yesterday.  At the end of the night, I had a poor connection and the downstream was poor, Downstream Power Level: Poor
Downstream power is poor (11.0dBmV). The recommended level is between -10dBmV to 10dBmV.

This morning, I noticed that after turning of my Vizio TV, the connection is now back at good again and when I turn the tv on it goes back to poor.  The Vizio is old (2003), came with built in wireless/wired internet.  I have noticed that the wireless never finds the Nighthawk or any other router except for the Verizon FIOS router.  Attempted to hardwire the tv to the EAX80 right next to it and TV states that it is disconnected.  I left the tv plugged into the EAX80 and powered it off.  So far everything is ok.  I usually have about 10-15 devices online/plugged at one time throughout the house such as Firesticks/airtv, cameras/doorbell, alarm clock, iPhones, iPad, and computers.  Just curious what everyone things. I can send the logs to Xfinity, but I know the game and they are going to blame the router and say it's not their problem, they were already here.  I can't tell if it is a hardware issue or is Xfinity playing games with me.  Any ideas/suggestions would be greatly appreciated.  I think I provided enough detail on my environment. Building is a condo 3 floors, and yes, the CAX80 is in the basement, no choice, about 1200sq ft. EAX80 and the Vizio tv is on the 2nd floor. Thank you.

[FURRYe38]

What Firmware version is currently loaded?
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...
https://kb.netgear.com/30008/How-do-I-view-or-clear-the-event-logs-on-my-NETGEAR-cable-modem-or-mode...

Power needs to be in between these specs for NG modems and gateways:

https://kb.netgear.com/24311/Power-level-guidelines-for-a-NETGEAR-cable-modem-router

Basements are not recommended places for wifi routers or gateways. Concrete and steel will inhibit good signal travel. 

[highfalutin60]

What Firmware version is currently loaded?

Firmware Version	V2.1.5.2
Cable Firmware Version	V1.02.08

Please post a copy and paste of the modems connection status and event log page. (Including the modem connection status 5/11/2024 for comparison)

Cable Connection

Cancel Apply

Cable Diagnostic Status:   Good Action:   Your setup looks fine. If you are still experience an internet issue, the Netgear Cable Knowledge Base can provide additional troubleshooting info. Internet Access:  Downstream Status:  Upstream Status:    Refresh Save Cable Diagnostic Info Advanced Information 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 651 MHz 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 256 QAM 44 651000000 Hz 9.1 dBmV 44.5 dB 0 0 2 Locked 256 QAM 13 465000000 Hz 9.7 dBmV 46.0 dB 0 0 3 Locked 256 QAM 14 471000000 Hz 9.7 dBmV 46.0 dB 0 0 4 Locked 256 QAM 15 477000000 Hz 9.9 dBmV 46.0 dB 0 0 5 Locked 256 QAM 16 483000000 Hz 9.8 dBmV 46.0 dB 0 0 6 Locked 256 QAM 17 489000000 Hz 9.7 dBmV 45.9 dB 0 0 7 Locked 256 QAM 18 495000000 Hz 9.7 dBmV 46.0 dB 0 0 8 Locked 256 QAM 19 501000000 Hz 9.7 dBmV 45.8 dB 0 0 9 Locked 256 QAM 20 507000000 Hz 9.6 dBmV 45.8 dB 0 0 10 Locked 256 QAM 21 513000000 Hz 9.4 dBmV 45.7 dB 0 0 11 Locked 256 QAM 22 519000000 Hz 9.4 dBmV 45.7 dB 0 0 12 Locked 256 QAM 23 525000000 Hz 9.4 dBmV 45.7 dB 0 0 13 Locked 256 QAM 24 531000000 Hz 9.2 dBmV 45.6 dB 0 0 14 Locked 256 QAM 25 537000000 Hz 9.1 dBmV 45.5 dB 0 0 15 Locked 256 QAM 26 543000000 Hz 9.0 dBmV 45.4 dB 0 0 16 Locked 256 QAM 27 549000000 Hz 8.9 dBmV 45.4 dB 0 0 17 Locked 256 QAM 28 555000000 Hz 8.8 dBmV 45.3 dB 0 0 18 Locked 256 QAM 29 561000000 Hz 8.7 dBmV 45.2 dB 0 0 19 Locked 256 QAM 30 567000000 Hz 8.7 dBmV 45.2 dB 0 0 20 Locked 256 QAM 31 573000000 Hz 8.6 dBmV 45.1 dB 0 0 21 Locked 256 QAM 32 579000000 Hz 8.6 dBmV 45.1 dB 0 0 22 Locked 256 QAM 33 585000000 Hz 8.6 dBmV 45.0 dB 0 0 23 Locked 256 QAM 34 591000000 Hz 8.8 dBmV 45.1 dB 0 0 24 Locked 256 QAM 35 597000000 Hz 8.8 dBmV 45.1 dB 0 0 25 Locked 256 QAM 36 603000000 Hz 8.8 dBmV 45.0 dB 0 0 26 Locked 256 QAM 37 609000000 Hz 8.8 dBmV 45.0 dB 0 0 27 Locked 256 QAM 38 615000000 Hz 8.9 dBmV 45.1 dB 0 0 28 Locked 256 QAM 39 621000000 Hz 9.0 dBmV 45.0 dB 0 0 29 Locked 256 QAM 40 627000000 Hz 8.9 dBmV 45.0 dB 0 0 30 Locked 256 QAM 41 633000000 Hz 8.9 dBmV 44.9 dB 0 0 31 Locked 256 QAM 42 639000000 Hz 9.2 dBmV 45.0 dB 0 0 32 Locked 256 QAM 43 645000000 Hz 9.0 dBmV 45.0 dB 0 0

Upstream Bonded Channels

Channel Lock Status US Channel Type Channel ID Symbol Rate Frequency Power 1 Locked ATDMA 18 5120 Ksym/sec 22800000 Hz 33.0 dBmV 2 Locked ATDMA 17 5120 Ksym/sec 16400000 Hz 33.0 dBmV 3 Locked ATDMA 19 5120 Ksym/sec 29200000 Hz 32.8 dBmV 4 Locked ATDMA 20 5120 Ksym/sec 35600000 Hz 32.8 dBmV 5 Not Locked Unknown 0 0 0 0.0 dBmV 6 Not Locked Unknown 0 0 0 0.0 dBmV 7 Not Locked Unknown 0 0 0 0.0 dBmV 8 Not Locked Unknown 0 0 0 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 ,3 193 690000000 Hz 9.58 dBmV 44.6 dB 508 ~ 3587 409167368 161578650 0 2 Locked 0 ,1 ,2 ,3 194 957000000 Hz 3.88 dBmV 42.4 dB 148 ~ 3947 409410584 191372405 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

Enable Extended Upstream Transmit Power

Current System Time:Sun May 12 15:35:30 2024

System Up Time:19:43:55

[highfalutin60]

Event Log

Clear Log Refresh

Time Priority Description Sun May 12 05:29:51 2024 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=94:18:65:a6:1f:63;CMTS-MAC=00:90:f0:63:04:00;CM-QOS=1.1;CM-VER=3.1; Sun May 12 03:48:07 2024 Notice (6) CM-STATUS message sent. Event Type Code: 24; Chan ID: 193; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 1 2.;CM-MAC=94:18:65:a6:1f:63;CMTS-MAC=00:90:f0:63:04:00;CM-QOS=1.1;CM-VER=3.1; Sun May 12 03:43:20 2024 Notice (6) CM-STATUS message sent. Event Type Code: 16; Chan ID: 193; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 1.;CM-MAC=94:18:65:a6:1f:63;CMTS-MAC=00:90:f0:63:04:00;CM-QOS=1.1;CM-VER=3.1; Sun May 12 02:45:36 2024 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=94:18:65:a6:1f:63;CMTS-MAC=00:90:f0:63:04:00;CM-QOS=1.1;CM-VER=3.1; Sun May 12 01:13:00 2024 Notice (6) CM-STATUS message sent. Event Type Code: 24; Chan ID: 193; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 1 2.;CM-MAC=94:18:65:a6:1f:63;CMTS-MAC=00:90:f0:63:04:00;CM-QOS=1.1;CM-VER=3.1; Sun May 12 01:10:07 2024 Notice (6) CM-STATUS message sent. Event Type Code: 16; Chan ID: 193; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 1 2.;CM-MAC=94:18:65:a6:1f:63;CMTS-MAC=00:90:f0:63:04:00;CM-QOS=1.1;CM-VER=3.1; Sun May 12 01:09:59 2024 Notice (6) CM-STATUS message sent. Event Type Code: 16; Chan ID: 193; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 2.;CM-MAC=94:18:65:a6:1f:63;CMTS-MAC=00:90:f0:63:04:00;CM-QOS=1.1;CM-VER=3.1; Sun May 12 01:09:12 2024 Notice (6) CM-STATUS message sent. Event Type Code: 16; Chan ID: 193; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 1.;CM-MAC=94:18:65:a6:1f:63;CMTS-MAC=00:90:f0:63:04:00;CM-QOS=1.1;CM-VER=3.1; Sat May 11 22:58:28 2024 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=94:18:65:a6:1f:63;CMTS-MAC=00:90:f0:63:04:00;CM-QOS=1.1;CM-VER=3.1; Sat May 11 22:35:43 2024 Notice (6) CM-STATUS message sent. Event Type Code: 4; Chan ID: 193 194; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=94:18:65:a6:1f:63;CMTS-MAC=00:90:f0:63:04:00;CM-QOS=1.1;CM-VER=3.1; Sat May 11 22:35:16 2024 Warning (5) MDD message timeout;CM-MAC=94:18:65:a6:1f:63;CMTS-MAC=00:90:f0:63:04:00;CM-QOS=1.1;CM-VER=3.1; Sat May 11 20:30:59 2024 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=94:18:65:a6:1f:63;CMTS-MAC=00:90:f0:63:04:00;CM-QOS=1.1;CM-VER=3.1; Sat May 11 19:53:02 2024 Critical (3) UCD invalid or channel unusable;CM-MAC=94:18:65:a6:1f:63;CMTS-MAC=00:90:f0:63:04:00;CM-QOS=1.1;CM-VER=3.1; Sat May 11 19:53:00 2024 Notice (6) DS profile assignment change. DS Chan ID: 33; Previous Profile: ; New Profile: 1 2 3.;CM-MAC=94:18:65:a6:1f:63;CMTS-MAC=00:90:f0:63:04:00;CM-QOS=1.1;CM-VER=3.1; Sat May 11 19:52:59 2024 Notice (6) DS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1 2 3.;CM-MAC=94:18:65:a6:1f:63;CMTS-MAC=00:90:f0:63:04:00;CM-QOS=1.1;CM-VER=3.1; Sat May 11 19:52:34 2024 Notice (6) TLV-11 - unrecognized OID;CM-MAC=94:18:65:a6:1f:63;CMTS-MAC=00:90:f0:63:04:00;CM-QOS=1.1;CM-VER=3.1; Thu Jan 1 00:00:51 1970 Notice (6) Honoring MDD; IP provisioning mode = IPv6 Thu Jan 1 00:00:45 1970 Critical (3) UCD invalid or channel unusable;CM-MAC=94:18:65:a6:1f:63;CMTS-MAC=00:90:f0:63:04:00;CM-QOS=1.1;CM-VER=3.1; Thu Jan 1 00:00:43 1970 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=94:18:65:a6:1f:63;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1; Sat May 11 16:26:17 2024 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=94:18:65:a6:1f:63;CMTS-MAC=00:90:f0:63:04:00;CM-QOS=1.1;CM-VER=3.1; Sat May 11 15:14:12 2024 Critical (3) UCD invalid or channel unusable;CM-MAC=94:18:65:a6:1f:63;CMTS-MAC=00:90:f0:63:04:00;CM-QOS=1.1;CM-VER=3.1; Thu Jan 1 00:00:46 1970 Critical (3) UCD invalid or channel unusable;CM-MAC=94:18:65:a6:1f:63;CMTS-MAC=00:90:f0:63:04:00;CM-QOS=1.1;CM-VER=3.1; Thu Jan 1 00:00:43 1970 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=94:18:65:a6:1f:63;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;

[FURRYe38]

Power levels are too high. I'd get a -6dbm cable coax line attenuator in between the modem and ISP cable line. 

Any Criticals, Errors or Warnings seen in the event logs needs to be reviewed and resolved by the ISP. Indicates a signal issue on the ISP line up to the modem. Have the ISP check the signal and line quality UP to the modem. Be sure the ISP provisions the modem correctly.

[highfalutin60]

Power levels are too high. I'd get a -6dbm cable coax line attenuator in between the modem and ISP cable line. 

Ok - got order the -3db but can return it.  Xfinity tech was already here yesterday, and he stated there was nothing wrong with my line/feed coming from the box to my condo unit.

Any Criticals, Errors or Warnings seen in the event logs needs to be reviewed and resolved by the ISP. Indicates a signal issue on the ISP line up to the modem. Have the ISP check the signal and line quality UP to the modem. Be sure the ISP provisions the modem correctly.

As for the event log, do I open another ticket with support? Xfinity tech has told me there is no issues so how do I fight this?  I can open a ticket and send them the logs but not sure if that will help.

As I stated before, I find it odd that with the Vizio tv turned off, the signal has been great all day. I have been doing spots checks all day. Just wondering if there could be an issue with the board on the tv causing issues on the line.

Thank You for looking at the logs, greatly appreciate it.

[FURRYe38]

All that is on the modem and ISP side. They need to check it out and resolve that.

Be sure your using good quality RG6 coax cable up to the modem. 
Start with removing any amplifiers, signal attenuators, or splitters from the coax.
From there check the line for kinks, damage, moisture in the line.
Check the connectors for improperly made ends, foil touching the copper coax line, loose connections, bad/old/cheap connectors, or corroded connections. Replace them if you do.

Nothing we can do here. 

[highfalutin60]

All that is on the modem and ISP side. They need to check it out and resolve that.

Be sure your using good quality RG6 coax cable up to the modem. 
Start with removing any amplifiers, signal attenuators, or splitters from the coax.
From there check the line for kinks, damage, moisture in the line.
Check the connectors for improperly made ends, foil touching the copper coax line, loose connections, bad/old/cheap connectors, or corroded connections. Replace them if you do.

So basically, you have validated everything I have done so far.  I had new RG6 coax cable installed in my condo less than 5 yrs ago..  As for Xfinity, they ran new cable from their box to each of the units maybe <5 years ago per my request because their service sucked so bad.  I don't have any amplifiers, attenuators or splitters from the coax.  I do have an extender installed on the Xfinity wire but get the same results with or without it.  The Xfinity tech provided me with their extender/extra coax because when Xfinity contractor ran the cables in the basement, they only ran it so far and not enough to reach any cable modem box that Xfinity or I have. Hope this makes sense.  Moving it would require the extender and more coax run from the basement to the 1st or 2nd floor.

Thank you again.