CM1000v2 restarting after Comcast repaired cable spans

[linkdupont]

I have a CM1000v2 and Comcast as my ISP. Yesterday they came by and put up new spans throughout my neighborhood, replacing a bunch that were torn down during a storm. Comcast no longer reports an outage in my area, but my modem is "offline" according to the Xfinity mobile app. The modem appears to be in some boot loop. It boots up and stays at the "Acquire Downstream Channel" stage of the Startup Procedure (with a Status of 0 Hz) for a couple minutes and then restarts itself. Comcast's chat support was pretty insistent that the problem is with my modem and that an onsite technician visit is necessary, but I'm skeptical that repairing cables outside could spontaneously cause my modem to fail like this. I tried a factory reset of the modem and attempted to "Activate" it again using the Xfinity mobile app, but it claims it cannot find my modem. This lends more credence to the theory that the problem is outside my house still. Is there anything I need to do with the CM1000v2 to ensure to Comcast support that the modem is fully functional? They've tried to punt me off to my "manufacturer's support" a couple times because it's not a Comcast-owned modem.

There is an Event Log entry:

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

(Note: the event log actually contains my modem’s MAC. I obfuscated it here for privacy.)

[plemans]

If its not even pulling the first downstream connection, then its a line issue. 

You can always tell them to bring out one of their modems and if it works, you'll be happy to rent theirs. 

But if the thing that changed, was they added new lines, tends to point at a line issue. Maybe they didn't tighten it all the way at the box. 

You can try moving your modem to right where the coax enters the home. If them pulling lines, degraded the signal (shouldn't happen), you'll get the best signal right where the coax enters. Plus it rules out the wiring in your home being the issue. Comcast charges if the issue is found within the home. 

[linkdupont]

It is 100% a line issue. They failed to reconnect the cable up at the box. I can see a freshly cut coax cable dangling up there by the pole. They refuse to send someone to fix it until Saturday.

[plemans]

Glad its not your equipement then!