CM500 connectivity issues - Cox has no advice - log shows variety of critical errors

[Gina11]

Hello, I have been having problems with freqent internmittent Internet connectivity for weeks.  I have a CM500-100NAS modem and an Orbi router with satellite.  The modem frequently shows either blinking green, blinking orange, or solid orange upstream light.  I check the Netgear gateway (which I can only do when the system is working) and everything shows "Good"  The firmware appears to be current for Cox: V1.01.11  I contacted Cox who refreshed and checked for errors on their end.  They also rebooted the modem.  The log shows a variety of errors:

Event Log

Time Priority Description 2020-3-17, 17:45:33 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=a0:04:60:c0:d2:a0;CMTS-MAC=00:bc:60:92:54:e9;CM-QOS=1.1;CM-VER=3.0; 2020-3-17, 17:46:00 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=a0:04:60:c0:d2:a0;CMTS-MAC=00:bc:60:92:54:e9;CM-QOS=1.1;CM-VER=3.0; 2020-3-17, 17:46:24 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=a0:04:60:c0:d2:a0;CMTS-MAC=00:bc:60:92:54:e9;CM-QOS=1.1;CM-VER=3.0; 2020-3-17, 17:46:24 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=a0:04:60:c0:d2:a0;CMTS-MAC=00:bc:60:92:54:e9;CM-QOS=1.1;CM-VER=3.0; 2020-3-17, 17:46:24 Critical (3) 16 consecutive T3 timeouts while trying to range on upstream channel 1;CM-MAC=a0:04:60:c0:d2:a0;CMTS-MAC=00:bc:60:92:54:e9;CM-QOS=1.1;CM-VER=3.0; 2020-3-17, 17:46:32 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=a0:04:60:c0:d2:a0;CMTS-MAC=00:bc:60:92:54:e9;CM-QOS=1.1;CM-VER=3.0; 2020-3-17, 17:47:00 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=a0:04:60:c0:d2:a0;CMTS-MAC=00:bc:60:92:54:e9;CM-QOS=1.1;CM-VER=3.0; 2020-3-17, 17:47:26 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=a0:04:60:c0:d2:a0;CMTS-MAC=00:bc:60:92:54:e9;CM-QOS=1.0;CM-VER=3.0; 2020-3-17, 17:48:22 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=a0:04:60:c0:d2:a0;CMTS-MAC=00:bc:60:92:54:e9;CM-QOS=1.1;CM-VER=3.0; 2020-3-17, 17:48:24 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a0:04:60:c0:d2:a0;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 2020-3-17, 17:48:59 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=a0:04:60:c0:d2:a0;CMTS-MAC=00:bc:60:92:54:e9;CM-QOS=1.1;CM-VER=3.0; 2020-3-17, 17:49:01 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a0:04:60:c0:d2:a0;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 2020-3-17, 17:49:18 Critical (3) No UCDs Received - Timeout;;CM-MAC=a0:04:60:c0:d2:a0;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 2020-3-17, 17:49:19 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a0:04:60:c0:d2:a0;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 2020-3-17, 17:49:36 Critical (3) No UCDs Received - Timeout;;CM-MAC=a0:04:60:c0:d2:a0;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 2020-3-17, 17:49:37 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a0:04:60:c0:d2:a0;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 2020-3-17, 17:49:54 Critical (3) No UCDs Received - Timeout;;CM-MAC=a0:04:60:c0:d2:a0;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 2020-3-17, 17:49:55 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a0:04:60:c0:d2:a0;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 2020-3-17, 17:50:12 Critical (3) No UCDs Received - Timeout;;CM-MAC=a0:04:60:c0:d2:a0;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 2020-3-17, 17:50:13 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a0:04:60:c0:d2:a0;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 2020-3-17, 17:50:30 Critical (3) No UCDs Received - Timeout;;CM-MAC=a0:04:60:c0:d2:a0;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 2020-3-17, 17:50:31 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a0:04:60:c0:d2:a0;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 2020-3-17, 17:50:48 Critical (3) No UCDs Received - Timeout;;CM-MAC=a0:04:60:c0:d2:a0;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 2020-3-17, 17:50:49 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a0:04:60:c0:d2:a0;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 2020-3-17, 17:51:06 Critical (3) No UCDs Received - Timeout;;CM-MAC=a0:04:60:c0:d2:a0;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 2020-3-17, 17:51:07 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a0:04:60:c0:d2:a0;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 2020-3-17, 17:51:24 Critical (3) No UCDs Received - Timeout;;CM-MAC=a0:04:60:c0:d2:a0;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 2020-3-17, 17:51:25 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a0:04:60:c0:d2:a0;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 2020-3-17, 17:51:42 Critical (3) No UCDs Received - Timeout;;CM-MAC=a0:04:60:c0:d2:a0;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 2020-3-17, 17:51:43 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a0:04:60:c0:d2:a0;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 2020-3-17, 17:52:00 Critical (3) No UCDs Received - Timeout;;CM-MAC=a0:04:60:c0:d2:a0;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 2020-3-17, 17:52:01 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a0:04:60:c0:d2:a0;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 2020-3-17, 17:52:18 Critical (3) No UCDs Received - Timeout;;CM-MAC=a0:04:60:c0:d2:a0;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 2020-3-17, 17:52:19 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a0:04:60:c0:d2:a0;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 2020-3-17, 18:07:41 Critical (3) Resetting the cable modem due to docsDevResetNow 1970-1-1, 00:00:22 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a0:04:60:c0:d2:a0;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 1970-1-1, 00:00:34 Notice (6) Honoring MDD; IP provisioning mode = IPv4 1970-1-1, 00:00:36 Warning (5) DHCP WARNING - Non-critical field invalid in response ;CM-MAC=a0:04:60:c0:d2:a0;CMTS-MAC=00:bc:60:92:54:e9;CM-QOS=1.0;CM-VER=3.0; 2020-3-17, 18:08:32 Notice (6) TLV-11 - unrecognized OID;CM-MAC=a0:04:60:c0:d2:a0;CMTS-MAC=00:bc:60:92:54:e9;CM-QOS=1.1;CM-VER=3.0; 2020-3-17, 18:10:00 Warning (5) Unicast DSID PSN startup error

[Gina11]

I attached the event log because it wasnt legible in the body of the post.  Reposting it here in case it is not legible.  Thank you for any help you can provide!

[plemans]

take a screen snip of the modem's connection page. it should show things like upload/download-snr/etc. 

that helps show your connection to the isp with the logs. 

if you have any splitter, attenuators, amplifiers in line, remove them. 

also prefereable to mode the mode to right where the coax enters the home. this prevents the wiring within the walls from being an issue. 

check all connectors for corrosion/loose/cheap/bad. 

[Gina11]

@plemans, thank you for your reply.  I did as you suggested. Checked connections, cords, etc. No splitters, etc.  As a precaution I also removed my T Mobile cell spot that was plugged into the router.

This morning the downstream link was blinking amber while the upstream was green solid. My dashboard also showed all 4 uplinks locked, unlike yesterday when I only had 1.  

Now it is 6 hours later, and I have reverted to the same situation. The upstream has amber blinking light and 1 upstream locked. I have attached a pdf of the dashboard as you requested.  The one labeled March 18 is from this morning, while the one labeled March 18 PM was taken just 7 hours later.  I appreciate any suggestions!

[Gina11]

@plemans here is the snippet from this morning.  

[plemans]

you have a lot of errors and issues with your line. You need to get your isp to check the line. 

[Gina11]

 Hello @plemans Since my last post, 3 separate Cox techs have visited on 3 consecutive days.  The wiring among 4 houses all seems to be intermingled and having problems.  Another service call is scheduled for today.  My next door neighbor still has no service at all, although mine has improved. I now have all my up and downstream channels locked.

Attached is a snippit of the dashboard.  We still have short periods of buffering. I heard from one of the Cox people that I still ought to replace my modem. Is he correct?  The other 3 didn't mention this.  My error log now only repeatedly shows this error and warning  Can you please explain what this means?  Thank you so much for your help and advice!

2020-3-25, 01:31:08	Critical (3)	Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=a0:04:60:c0:d2:a0;CMTS-MAC=00:bc:60:92:54:e9;CM-QOS=1.1;CM-VER=3.0;
2020-3-25, 01:31:08	Warning (5)	Dynamic Range Window violation

[plemans]

You still have quite a few errors on your line. 

the logs usually reference an issue contacting back to the cmts (isp connection basically)

The cm500 is a decent modem. I'd have cox get your line issues fixed first before replacing it. 

Unless you plan on upgrading to gigabit 🙂 Then you need a docsis 3.1 modem.