2 Messages

Thursday, March 16th, 2023 9:14 PM

Netgear CM1200 (SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing)

My Gateway or modem, netgear cm1200 mysteriously has this critical fail nightly right around midnight.  The only way to annoyingly resolve the issue is to restart the modem, daily.  I've seen a few other posts on this community with the same issue without advertised resolution,  seems to go to DM's for some reason.  I would very much like to resolve this issue as customer service wants to keep restarting the modem when it's working, not addressing the midnight issue, at all.  I've also been told we need to buy a newer modem, I don't think docsis 3.2 is out yet and even if it is, not likely Xfininty is using it yet.  I've also been asked if the cables are tight, because loose cables assert at a specific time nightly with a sync fail.  

Pls help


Official Employee


1.2K Messages

3 months ago

Hi there, @user_3a60f0. We would be happy to further help with this issue. Once we find a solution we can ensure the thread gets updated to help others if they run into the same problem. We recommend getting a new modem if your modem does not fully support your speed tier. I have seen cases where there is intermittent or slow internet related to the boot file (provisioning) as you are suspecting. The file will be correct but since the modem does not support the speed tier it causes issues with the service. I don't know why that is but have seen it. For instance, if you subscribe to 1000 Mbps, but your modem only supports 949 Mbps, then we would recommend getting a modem that goes faster or downgrading to a speed tier your modem is capable of. Have you had a provisioning signal sent to see if that improves the problem or no one was able to do that?

forum icon

New to the Community?

Start Here