Skip to main content

I have an Arris S33 modem which I activated on May 27, which replaced a Comcast Xfinity supplied gateway.

Since activation, I’ve discovered my internet connection drops every day at around 1AM and connection returns within 5 minutes.  Never longer than that. The schedule is the same every day and has not changed.  It is not just Wi-Fi but also when connected via ethernet on my desktop computer.

I have an Amplifi Alien mesh router which is up-to-date firmware wise but I've already ruled it out as the culprit. During my weeks of troubleshooting, I've been on my desktop computer directly connected to the modem as well.

When I lose connection at 1:00 AM, my Xfinity app says it is "Offline".  My Alien app shows device is not connected to the internet and "No Internet Connection" is displayed on it's screen.

Looking for some help in further troubleshooting this issue.  Where should I be looking especially when the connection drops at same time every day?

I’m working simultaneously with Comcast on this but would like to rule out the S33.

Thanks.

Update:  In my Event Log, I see this entry happening every day.

 

SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=**:**:**:**:**:**;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;

 

(edit: CM-MAC information removed)

I’m just noticing that Date & Time are wrong in the Event Log.  How do I correct it?

 

(edit: CM-MAC information removed)
 

31/12/1969
16:00:20		 3 CMSTATUS:US_Diplexer_Mode_Change:TLV-21.1, 5-42MHz.
31/12/1969
16:00:34		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.2, 108MHz.
31/12/1969
16:00:34		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.3, 1002MHz.
31/12/1969
16:00:34		 3 CMSTATUS:US_Diplexer_Mode_Change:TLV-84.1, 5-42MHz.
31/12/1969
16:00:16		 3 CMSTATUS:US_Diplexer_Mode_Change:Init, 5-42MHz.
31/12/1969
16:00:19		 3 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=**:**:**:**:**:**;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
31/12/1969
16:00:20		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.2, 258MHz.
31/12/1969
16:00:20		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.3, 1002MHz.
31/12/1969
16:00:20		 3 CMSTATUS:US_Diplexer_Mode_Change:TLV-21.1, 5-42MHz.
31/12/1969
16:00:33		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.2, 108MHz.
31/12/1969
16:00:33		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.3, 1002MHz.
31/12/1969
16:00:33		 3 CMSTATUS:US_Diplexer_Mode_Change:TLV-84.1, 5-42MHz.
29/6/2023
00:56:42		 3 No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
31/12/1969
16:00:16		 3 CMSTATUS:US_Diplexer_Mode_Change:Init, 5-42MHz.
31/12/1969
16:00:19		 3 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=**:**:**:**:**:**;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
31/12/1969
16:00:21		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.2, 258MHz.
31/12/1969
16:00:21		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.3, 1002MHz.
31/12/1969
16:00:22		 3 CMSTATUS:US_Diplexer_Mode_Change:TLV-21.1, 5-42MHz.
31/12/1969
16:00:35		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.2, 108MHz.
31/12/1969
16:00:35		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.3, 1002MHz.
31/12/1969
16:00:35		 3 CMSTATUS:US_Diplexer_Mode_Change:TLV-84.1, 5-42MHz.
31/12/1969
16:00:16		 3 CMSTATUS:US_Diplexer_Mode_Change:Init, 5-42MHz.
31/12/1969
16:00:19		 3 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=**:**:**:**:**:**;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
31/12/1969
16:00:21		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.2, 258MHz.
31/12/1969
16:00:21		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.3, 1002MHz.
31/12/1969
16:00:21		 3 CMSTATUS:US_Diplexer_Mode_Change:TLV-21.1, 5-42MHz.
31/12/1969
16:00:34		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.2, 108MHz.
31/12/1969
16:00:34		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.3, 1002MHz.
31/12/1969
16:00:34		 3 CMSTATUS:US_Diplexer_Mode_Change:TLV-84.1, 5-42MHz.
31/12/1969
16:00:16		 3 CMSTATUS:US_Diplexer_Mode_Change:Init, 5-42MHz.
31/12/1969
16:00:19		 3 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=**:**:**:**:**:**;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
31/12/1969
16:00:22		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.2, 258MHz.
31/12/1969
16:00:22		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.3, 1002MHz.
31/12/1969
16:00:22		 3 CMSTATUS:US_Diplexer_Mode_Change:TLV-21.1, 5-42MHz.
31/12/1969
16:00:36		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.2, 108MHz.
31/12/1969
16:00:36		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.3, 1002MHz.
31/12/1969
16:00:36		 3 CMSTATUS:US_Diplexer_Mode_Change:TLV-84.1, 5-42MHz.
31/12/1969
16:00:16		 3 CMSTATUS:US_Diplexer_Mode_Change:Init, 5-42MHz.
31/12/1969
16:00:19		 3 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=**:**:**:**:**:**;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
31/12/1969
16:00:20		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.2, 258MHz.
31/12/1969
16:00:20		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.3, 1002MHz.
31/12/1969
16:00:20		 3 CMSTATUS:US_Diplexer_Mode_Change:TLV-21.1, 5-42MHz.
31/12/1969
16:00:33		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.2, 108MHz.
31/12/1969
16:00:33		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.3, 1002MHz.
31/12/1969
16:00:33		 3 CMSTATUS:US_Diplexer_Mode_Change:TLV-84.1, 5-42MHz.
2/7/2023
15:25:11		 3 Successful LAN WebGUI login from ***.***.***.*** on 23/07/02 at 3:25 PM.
2/7/2023
17:19:15		 3 Successful LAN WebGUI login from ***.***.***.*** on 23/07/02 at 5:19 PM.
31/12/1969
16:00:16		 3 CMSTATUS:US_Diplexer_Mode_Change:Init, 5-42MHz.
31/12/1969
16:00:20		 3 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=**:**:**:**:**:**;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
31/12/1969
16:00:22		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.2, 258MHz.
31/12/1969
16:00:22		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.3, 1002MHz.
31/12/1969
16:00:22		 3 CMSTATUS:US_Diplexer_Mode_Change:TLV-21.1, 5-42MHz.
31/12/1969
16:00:36		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.2, 108MHz.
31/12/1969
16:00:36		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.3, 1002MHz.
31/12/1969
16:00:36		 3 CMSTATUS:US_Diplexer_Mode_Change:TLV-84.1, 5-42MHz.
31/12/1969
16:00:16		 3 CMSTATUS:US_Diplexer_Mode_Change:Init, 5-42MHz.
31/12/1969
16:00:20		 3 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=**:**:**:**:**:**;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
31/12/1969
16:00:21		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.2, 258MHz.
31/12/1969
16:00:21		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.3, 1002MHz.
31/12/1969
16:00:21		 3 CMSTATUS:US_Diplexer_Mode_Change:TLV-21.1, 5-42MHz.
31/12/1969
16:00:35		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.2, 108MHz.
31/12/1969
16:00:35		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.3, 1002MHz.
31/12/1969
16:00:35		 3 CMSTATUS:US_Diplexer_Mode_Change:TLV-84.1, 5-42MHz.
31/12/1969
16:00:16		 3 CMSTATUS:US_Diplexer_Mode_Change:Init, 5-42MHz.
31/12/1969
16:00:19		 3 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=**:**:**:**:**:**;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
31/12/1969
16:00:21		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.2, 258MHz.
31/12/1969
16:00:21		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.3, 1002MHz.
31/12/1969
16:00:21		 3 CMSTATUS:US_Diplexer_Mode_Change:TLV-21.1, 5-42MHz.
31/12/1969
16:00:35		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.2, 108MHz.
31/12/1969
16:00:35		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.3, 1002MHz.
31/12/1969
16:00:35		 3 CMSTATUS:US_Diplexer_Mode_Change:TLV-84.1, 5-42MHz.
3/7/2023
00:56:41		 3 No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
31/12/1969
16:00:16		 3 CMSTATUS:US_Diplexer_Mode_Change:Init, 5-42MHz.
31/12/1969
16:00:19		 3 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=**:**:**:**:**:**;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
31/12/1969
16:00:20		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.2, 258MHz.
31/12/1969
16:00:20		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.3, 1002MHz.
31/12/1969
16:00:20		 3 CMSTATUS:US_Diplexer_Mode_Change:TLV-21.1, 5-42MHz.
31/12/1969
16:00:33		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.2, 108MHz.
31/12/1969
16:00:33		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.3, 1002MHz.
31/12/1969
16:00:33		 3 CMSTATUS:US_Diplexer_Mode_Change:TLV-84.1, 5-42MHz.
31/12/1969
16:00:16		 3 CMSTATUS:US_Diplexer_Mode_Change:Init, 5-42MHz.
31/12/1969
16:00:19		 3 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=**:**:**:**:**:**;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
31/12/1969
16:00:22		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.2, 258MHz.
31/12/1969
16:00:22		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.3, 1002MHz.
31/12/1969
16:00:22		 3 CMSTATUS:US_Diplexer_Mode_Change:TLV-21.1, 5-42MHz.
31/12/1969
16:00:35		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.2, 108MHz.
31/12/1969
16:00:35		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.3, 1002MHz.
31/12/1969
16:00:35		 3 CMSTATUS:US_Diplexer_Mode_Change:TLV-84.1, 5-42MHz.
4/7/2023
00:53:39		 3 No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
31/12/1969
16:00:16		 3 CMSTATUS:US_Diplexer_Mode_Change:Init, 5-42MHz.
31/12/1969
16:00:19		 3 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=**:**:**:**:**:**;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
31/12/1969
16:00:20		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.2, 258MHz.
31/12/1969
16:00:20		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.3, 1002MHz.
31/12/1969
16:00:20		 3 CMSTATUS:US_Diplexer_Mode_Change:TLV-21.1, 5-42MHz.
31/12/1969
16:00:25		 6 Honoring MDD; IP provisioning mode = IPv6
31/12/1969
16:00:33		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.2, 108MHz.
31/12/1969
16:00:33		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.3, 1002MHz.
31/12/1969
16:00:33		 3 CMSTATUS:US_Diplexer_Mode_Change:TLV-84.1, 5-42MHz.
4/7/2023
00:56:03		 6 DS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1 2 3.;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
4/7/2023
14:51:48		 3 Successful LAN WebGUI login from ***.***.***.*** on 23/07/04 at 2:51 PM.
Terms & ConditionsCookie settings