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SYNC Timing Synchronization failure

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SYNC Timing Synchronization failure

Hello - I am running an Arris SB8200 as per Xfinity's website indicating it is an approved modem.  I am experiencing latency and connection drops.  The modem connects directly to the feed line at the demarc at the house.  We have been having this error off and on for about 90 days and replaced an older Arris modem because of it.  Xfinity tech replaced a bad connector at the street that had a 90 degree bend and too long of center conductor and said that was our problem.  Four days later it's back.  See error log below.

 

Phone tech keeps trying to tell me the modem needs configured and they cant do it because it's CPE.  That does not seem like an acceptable answer to me since it's on the list of approved modems.

 

Any advice?

 

SYNC Timing Synchronization failure and other error messages below.

 

7/12/20 7:46840001003"SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=c8:63:fc:a2:bb:11;CMTS-MAC=00:01:5c:6f:f0:62;CM-QOS=1.1;CM-VER=3.1;"   
7/12/20 7:44840001003"SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=c8:63:fc:a2:bb:11;CMTS-MAC=00:01:5c:6f:f0:62;CM-QOS=1.1;CM-VER=3.1;"   
7/12/20 7:44840001003"SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=c8:63:fc:a2:bb:11;CMTS-MAC=00:01:5c:6f:f0:62;CM-QOS=1.1;CM-VER=3.1;"   
7/12/20 7:41840001003"SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=c8:63:fc:a2:bb:11;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;"  
7/12/20 7:37820004003"Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=c8:63:fc:a2:bb:11;CMTS-MAC=00:01:5c:6f:f0:62;CM-QOS=1.1;CM-VER=3.1;"
7/12/20 7:37840001003"SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=c8:63:fc:a2:bb:11;CMTS-MAC=00:01:5c:6f:f0:62;CM-QOS=1.1;CM-VER=3.1;"   
7/12/20 7:36820004003"Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=c8:63:fc:a2:bb:11;CMTS-MAC=00:01:5c:6f:f0:62;CM-QOS=1.1;CM-VER=3.1;"
7/12/20 7:36840001003"SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=c8:63:fc:a2:bb:11;CMTS-MAC=00:01:5c:6f:f0:62;CM-QOS=1.1;CM-VER=3.1;"   
7/12/20 7:35820004003"Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=c8:63:fc:a2:bb:11;CMTS-MAC=00:01:5c:6f:f0:62;CM-QOS=1.1;CM-VER=3.1;"
7/12/20 7:35840001003"SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=c8:63:fc:a2:bb:11;CMTS-MAC=00:01:5c:6f:f0:62;CM-QOS=1.1;CM-VER=3.1;"   
7/12/20 7:35820004003"Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=c8:63:fc:a2:bb:11;CMTS-MAC=00:01:5c:6f:f0:62;CM-QOS=1.1;CM-VER=3.1;"
7/12/20 7:35840001003"SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=c8:63:fc:a2:bb:11;CMTS-MAC=00:01:5c:6f:f0:62;CM-QOS=1.1;CM-VER=3.1;"   
7/12/20 7:34840001003"SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=c8:63:fc:a2:bb:11;CMTS-MAC=00:01:5c:6f:f0:62;CM-QOS=1.1;CM-VER=3.1;"   
7/12/20 7:34840001003"SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=c8:63:fc:a2:bb:11;CMTS-MAC=00:01:5c:6f:f0:62;CM-QOS=1.1;CM-VER=3.1;"   

 

07/11/2020 05:31820005003"Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=c8:63:fc:a2:bb:11;CMTS-MAC=00:01:5c:6f:f0:62;CM-QOS=1.1;CM-VER=3.1;"
07/11/2020 00:23820005003"Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=c8:63:fc:a2:bb:11;CMTS-MAC=00:01:5c:6f:f0:62;CM-QOS=1.1;CM-VER=3.1;"
07/10/2020 23:59820004003"Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=c8:63:fc:a2:bb:11;CMTS-MAC=00:01:5c:6f:f0:62;CM-QOS=1.1;CM-VER=3.1;"
07/10/2020 23:59820002003"No Ranging Response received - T3 time-out;CM-MAC=c8:63:fc:a2:bb:11;CMTS-MAC=00:01:5c:6f:f0:62;CM-QOS=1.1;CM-VER=3.1;"
07/10/2020 23:59820004003"Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=c8:63:fc:a2:bb:11;CMTS-MAC=00:01:5c:6f:f0:62;CM-QOS=1.1;CM-VER=3.1;"
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Expert

Re: SYNC Timing Synchronization failure

Are you actually experiencing any connectivity problems or just focusing on the log entries ?



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Re: SYNC Timing Synchronization failure

Connectivity issues. I've had multiple techs come out and they always find a problem outside, which they claim will fix the problem. I have another one coming in a few days because of the connectivity issue (yet again). I wish Xfinity realized it's not an issue with owners' equipment; it must be something on their end.

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Expert

Re: SYNC Timing Synchronization failure

Please also post the *Downstream Power Level*, the *Upstream Power Level*, and the *SNR* (Signal to Noise Ratio) numbers.




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