ARRIS S33 cable modem event log shows 31/12/1969 date when internet connection is dropped

you beat me to it!

It's not a race. The more the merrier I always say.

I was wondering how exactly the ToD system works. Does it use some kind of local NTP server at the headend? 

EXAMPLE

26/7/2023
10:39:26 3 SYNC Timing Synchronization failure - 

31/12/1969
17:00:15 3 CMSTATUS:US_Diplexer_Mode_Change:Init, 5-42MHz.
31/12/1969
17:00:19 3 SYNC Timing Synchronization failure - 
31/12/1969
17:00:21 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.2, 108MHz.
31/12/1969
17:00:21 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.3, 1002MHz.
31/12/1969
17:00:21 3 CMSTATUS:US_Diplexer_Mode_Change_Ignored:TLV-21.1, 85MHz.
31/12/1969
17:00:21 3 UCD invalid or channel unusable;
31/12/1969
17:00:25 3 No Ranging Response received - T3 time-out;
31/12/1969
17:00:33 6 Honoring MDD; IP provisioning mode = IPv4
31/12/1969
17:00:35 5 DHCP WARNING - Non-critical field invalid in response ;
26/7/2023
12:52:26 3 CMSTATUS:US_Diplexer_Mode_Change:TLV-84.1, 5-85MHz.
26/7/2023
12:52:26 3 CMSTATUS:US_Diplexer_Mode_Change_Ignored:Other, 85MHz.

17:00:25 3 No Ranging Response received - T3 time-out;

That is the main error that made you lose connection. Can you post your signal levels?

Your upstream looks low. Usually the lower the better, but if there is intermittent noise floor problem low upstream can be a issue. Its basically like if you are at a party and trying to whisper to be heard. If there is high background noise, you can't be heard very well and there is T3 errors. However, when the party stops, it is very quiet so you don't have to talk loud so your upstream doesn't have to be high.

I would suggest having a technician investigate the T3 errors. Maybe a attenuator might help. Don't mention the date error. That will only confuse the technician IMO.

::edit:: I assume you have bypassed all the splitters in the house BTW. Please confirm that.

COX will never get back to you regarding this issue. I finally got a hold of a tech savy person that aggred to place a note to my complaint so that the I.T. people would address the problem of the wrong date and time in their equipment. Now that issue has been taken care of it is now the process of them every day setting the levels for download speed then upload speed. Its a balancing act to do this properly and the contractors do not have the big picture in mind when they just throw attenuators in line and connect your house to the wrong port. I pay for the 1 gig and 100 meg package and it is not being delivered as of yet, just have to be patient.

try replacing cable wires/splitters/barrel connectors, and see if that helps. Sometimes we get a bent cable wire, and that can cause all kinds of issues, causing the RF signal to get reflected backwards, and causing problems for all devices in the home.