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DukerOfHazzard's avatar
DukerOfHazzard
Aspirant
Feb 17, 2021
Solved

CM500 signal keeps dropping

Hello everyone,

 

Like many other people before me, I am having issues with my CM500 cable modem. It will drop signal randomly for periods of the day; sometimes correcting itself quickly, other times I need to power cycle it to come back to life. Other times it's fine for 2-3 days without incident. When it does go down, the upstream LED blinks. We have no amplifiers or attenuators, but we do have one splitter that was replaced after we started having issues. Below is the chart most people ask for when examining these issues. I am unsure on how to bring up the modem logs, I can post them if anyone can tell me how to access them. Any help is greatly appreciated!

 

Downstream Bonded Channels
Channel Lock Status Modulation Channel ID Frequency Power SNR Correctables Uncorrectables
1LockedQAM25613477000000 Hz-0.7 dBmV43.2 dB2147
2LockedQAM25614483000000 Hz-0.5 dBmV43.4 dB00
3LockedQAM25615489000000 Hz-0.5 dBmV43.4 dB00
4LockedQAM25616495000000 Hz-0.3 dBmV43.6 dB00
5LockedQAM25617519000000 Hz0.5 dBmV44.1 dB00
6LockedQAM25618525000000 Hz0.4 dBmV44 dB00
7LockedQAM25619531000000 Hz-0.1 dBmV43.3 dB00
8LockedQAM25620537000000 Hz-0.6 dBmV43 dB80
9LockedQAM25621543000000 Hz-0.8 dBmV43.3 dB00
10LockedQAM25622549000000 Hz-1.1 dBmV43 dB00
11LockedQAM25623555000000 Hz-1.1 dBmV42.8 dB00
12LockedQAM25624561000000 Hz-1 dBmV43 dB00
13LockedQAM25625567000000 Hz-1 dBmV42.9 dB00
14LockedQAM25626573000000 Hz-1 dBmV42.9 dB00
15LockedQAM25627579000000 Hz-1 dBmV42.8 dB00
16LockedQAM25628585000000 Hz-1 dBmV42.9 dB00
 
Upstream Bonded Channels
Channel Lock Status US Channel Type Channel ID Symbol Rate Frequency Power
1LockedATDMA25120 Ksym/sec30100000 Hz47.8 dBmV
2LockedATDMA15120 Ksym/sec36500000 Hz47 dBmV
3LockedATDMA35120 Ksym/sec23700000 Hz47.5 dBmV
4LockedATDMA45120 Ksym/sec17300000 Hz47.8 dBmV
  • plemans's avatar
    plemans
    Feb 17, 2021

    You're getting a lot of timeouts. Thats when the modem isn't connecting back to the cmts. Tends to be line issues. 

    You can check your side of the line again for kinks, damage, loose/old/bad/corroded connectors. If you can't find anything, the isp needs to check the line 

3 Replies

    • DukerOfHazzard's avatar
      DukerOfHazzard
      Aspirant
      Feb 17, 2021
      Time Priority Description
      1970-1-1, 00:01:47Notice (6)Honoring MDD; IP provisioning mode = IPv6
      1970-1-1, 00:00:28Critical (3)No Ranging Response received - T3 time-out;CM-MAC=9c:c9:eb:4c:21:30;CMTS-MAC=00:01:5c:96:48:53;CM-QOS=1.0;CM-VER=3.0;
      1970-1-1, 00:00:22Critical (3)SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=9c:c9:eb:4c:21:30;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;
      2021-2-16, 19:38:00Critical (3)Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=9c:c9:eb:4c:21:30;CMTS-MAC=00:01:5c:96:48:53;CM-QOS=1.1;CM-VER=3.0;
      2021-2-16, 19:10:25Critical (3)Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=9c:c9:eb:4c:21:30;CMTS-MAC=00:01:5c:96:48:53;CM-QOS=1.1;CM-VER=3.0;
      2021-2-16, 19:10:24Critical (3)16 consecutive T3 timeouts while trying to range on upstream channel 0;CM-MAC=9c:c9:eb:4c:21:30;CMTS-MAC=00:01:5c:96:48:53;CM-QOS=1.1;CM-VER=3.0;
      2021-2-16, 19:10:24Critical (3)Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=9c:c9:eb:4c:21:30;CMTS-MAC=00:01:5c:96:48:53;CM-QOS=1.1;CM-VER=3.0;
      2021-2-16, 19:10:05Critical (3)Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=9c:c9:eb:4c:21:30;CMTS-MAC=00:01:5c:96:48:53;CM-QOS=1.1;CM-VER=3.0;
      2021-2-16, 19:10:05Critical (3)16 consecutive T3 timeouts while trying to range on upstream channel 1;CM-MAC=9c:c9:eb:4c:21:30;CMTS-MAC=00:01:5c:96:48:53;CM-QOS=1.1;CM-VER=3.0;
      2021-2-16, 19:10:05Critical (3)Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=9c:c9:eb:4c:21:30;CMTS-MAC=00:01:5c:96:48:53;CM-QOS=1.1;CM-VER=3.0;
      2021-2-16, 19:08:56Critical (3)Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=9c:c9:eb:4c:21:30;CMTS-MAC=00:01:5c:96:48:53;CM-QOS=1.1;CM-VER=3.0;
      1970-1-1, 00:00:21Critical (3)SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=9c:c9:eb:4c:21:30;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;
      2021-2-16, 18:41:37Critical (3)16 consecutive T3 timeouts while trying to range on upstream channel 1;CM-MAC=9c:c9:eb:4c:21:30;CMTS-MAC=00:01:5c:96:48:53;CM-QOS=1.1;CM-VER=3.0;
      2021-2-16, 18:41:37Critical (3)Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=9c:c9:eb:4c:21:30;CMTS-MAC=00:01:5c:96:48:53;CM-QOS=1.1;CM-VER=3.0;
      2021-2-16, 18:40:30Critical (3)Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=9c:c9:eb:4c:21:30;CMTS-MAC=00:01:5c:96:48:53;CM-QOS=1.1;CM-VER=3.0;
      2021-2-14, 11:59:17Critical (3)Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=9c:c9:eb:4c:21:30;CMTS-MAC=00:01:5c:96:48:53;CM-QOS=1.1;CM-VER=3.0;
      2021-2-14, 00:32:07Critical (3)Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=9c:c9:eb:4c:21:30;CMTS-MAC=00:01:5c:96:48:53;CM-QOS=1.1;CM-VER=3.0;
      2021-2-14, 00:32:06Critical (3)16 consecutive T3 timeouts while trying to range on upstream channel 0;CM-MAC=9c:c9:eb:4c:21:30;CMTS-MAC=00:01:5c:96:48:53;CM-QOS=1.1;CM-VER=3.0;
      2021-2-14, 00:32:06Critical (3)Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=9c:c9:eb:4c:21:30;CMTS-MAC=00:01:5c:96:48:53;CM-QOS=1.1;CM-VER=3.0;
      2021-2-12, 05:40:42Critical (3)Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=9c:c9:eb:4c:21:30;CMTS-MAC=00:01:5c:96:48:53;CM-QOS=1.1;CM-VER=3.0;
      2021-2-12, 03:23:26Critical (3)No Ranging Response received - T3 time-out;CM-MAC=9c:c9:eb:4c:21:30;CMTS-MAC=00:01:5c:96:48:53;CM-QOS=1.0;CM-VER=3.0;
      2021-2-12, 03:22:55Critical (3)Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=9c:c9:eb:4c:21:30;CMTS-MAC=00:01:5c:96:48:53;CM-QOS=1.1;CM-VER=3.0;
      2021-2-12, 03:18:54Critical (3)Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=9c:c9:eb:4c:21:30;CMTS-MAC=00:01:5c:96:48:53;CM-QOS=1.1;CM-VER=3.0;
      2021-2-12, 03:18:53Critical (3)16 consecutive T3 timeouts while trying to range on upstream channel 2;CM-MAC=9c:c9:eb:4c:21:30;CMTS-MAC=00:01:5c:96:48:53;CM-QOS=1.1;CM-VER=3.0;
      2021-2-12, 03:18:53Critical (3)Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=9c:c9:eb:4c:21:30;CMTS-MAC=00:01:5c:96:48:53;CM-QOS=1.1;CM-VER=3.0;
      2021-2-12, 03:18:14Critical (3)Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=9c:c9:eb:4c:21:30;CMTS-MAC=00:01:5c:96:48:53;CM-QOS=1.1;CM-VER=3.0;
      2021-2-12, 03:18:11Critical (3)16 consecutive T3 timeouts while trying to range on upstream channel 3;CM-MAC=9c:c9:eb:4c:21:30;CMTS-MAC=00:01:5c:96:48:53;CM-QOS=1.1;CM-VER=3.0;
      2021-2-12, 03:18:11Critical (3)Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=9c:c9:eb:4c:21:30;CMTS-MAC=00:01:5c:96:48:53;CM-QOS=1.1;CM-VER=3.0;
      2021-2-12, 03:17:03Critical (3)Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=9c:c9:eb:4c:21:30;CMTS-MAC=00:01:5c:96:48:53;CM-QOS=1.1;CM-VER=3.0;
      2021-2-9, 14:31:20Critical (3)No Ranging Response received - T3 time-out;CM-MAC=9c:c9:eb:4c:21:30;CMTS-MAC=00:01:5c:96:48:53;CM-QOS=1.0;CM-VER=3.0;
      2021-2-9, 14:30:49Critical (3)Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=9c:c9:eb:4c:21:30;CMTS-MAC=00:01:5c:96:48:53;CM-QOS=1.1;CM-VER=3.0;
      2021-2-9, 12:58:19Critical (3)Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=9c:c9:eb:4c:21:30;CMTS-MAC=00:01:5c:96:48:53;CM-QOS=1.1;CM-VER=3.0;
      2021-2-9, 12:58:18Critical (3)16 consecutive T3 timeouts while trying to range on upstream channel 0;CM-MAC=9c:c9:eb:4c:21:30;CMTS-MAC=00:01:5c:96:48:53;CM-QOS=1.1;CM-VER=3.0;
      2021-2-9, 12:58:18Critical (3)Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=9c:c9:eb:4c:21:30;CMTS-MAC=00:01:5c:96:48:53;CM-QOS=1.1;CM-VER=3.0;
      2021-2-9, 12:57:10Critical (3)Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=9c:c9:eb:4c:21:30;CMTS-MAC=00:01:5c:96:48:53;CM-QOS=1.1;CM-VER=3.0;
      2021-2-9, 12:00:32Critical (3)No Ranging Response received - T3 time-out;CM-MAC=9c:c9:eb:4c:21:30;CMTS-MAC=00:01:5c:96:48:53;CM-QOS=1.0;CM-VER=3.0;
      2021-2-9, 12:00:24Critical (3)Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=9c:c9:eb:4c:21:30;CMTS-MAC=00:01:5c:96:48:53;CM-QOS=1.1;CM-VER=3.0;
      2021-2-9, 11:59:33Critical (3)Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=9c:c9:eb:4c:21:30;CMTS-MAC=00:01:5c:96:48:53;CM-QOS=1.1;CM-VER=3.0;
      2021-2-9, 11:58:34Critical (3)No Ranging Response received - T3 time-out;CM-MAC=9c:c9:eb:4c:21:30;CMTS-MAC=00:01:5c:96:48:53;CM-QOS=1.0;CM-VER=3.0;
      2021-2-9, 11:58:06Critical (3)Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=9c:c9:eb:4c:21:30;CMTS-MAC=00:01:5c:96:48:53;CM-QOS=1.1;CM-VER=3.0;
      • plemans's avatar
        plemans
        Guru - Experienced User
        Feb 17, 2021

        You're getting a lot of timeouts. Thats when the modem isn't connecting back to the cmts. Tends to be line issues. 

        You can check your side of the line again for kinks, damage, loose/old/bad/corroded connectors. If you can't find anything, the isp needs to check the line