Constant disconnects - Xfinity cant detect signal - Netgear CM1150V Modem

[thenixhex311]

Oh man, that was frustrating...i had the whole thing typed...switched to HTML and I lost it all. Have a Netgear CM1150V modem with Xfinity Gigabit. Purchased it in Feb. Constant connection issues as of late. Only remedy is to unplug/replug, but this needs done at least 5-6x a day. Xfinity apps/websites say 'cant find a signal/modem is offline' (but I'm on a wired computer now typing this...waiting for it to go out). Found out about the backend (192.168.100.1) today and was able to get in to see some values. I can't seem to attach more than one image, but one is the main log, the other is the event log which seems to have a BUNCH of Critical T3 errors. I'm assuming this is what is causing my headaches. I have a Comcast technician coming out tomorrow at 2pm eastern...anything I should 'prepare' for him to be able to throw back (e.g. "well I have a bunch of T3 errors in my log, maybe theres a noise filter, etc.") so I don't let them pull a fast one and say they don't see anything or want to check wires, etc. I've attached an image of the event log to this message. Here's a link to the imgur for the main status screen: https://imgur.com/tpdeAyr

[FURRYe38]

Have the ISP check the signal and line quality UP to the modem. Be sure the ISP provisions the modem correctly.
Be sure there are no coax cable line splitters in the between the modem and ISP service box. 
Be sure your using good quality RG6 coax cable up to the modem. 
Be sure to power OFF the modem for 1 minute them back ON.
https://community.netgear.com/t5/Cable-Modems-Routers/General-info-and-Troubleshooting-for-Cable-Mod...
https://highspeed.tips/docsis-events/

What brand and model is the wifi router connected to the CM modem? 

[thenixhex311]

My router is a NETGEAR - Orbi AX4200
Just got it Friday

[FURRYe38]

Ok. Make sure the ISP gets good service and signal to the modem first. Hopefully they can figure out the problem on there side. 

[thenixhex311]

ok, so an Xfinity guy came out Tuesday and did a test at the outside connection of the house. There was a 3-way splitter he replaced. One line runs into the house that goes to a DVR cable box. Two other lines run up the house behind the gutter, one going to where the modem is, the other eventually to the master bedroom is. Once he disconnected the line that ran to the bedroom, he said the noise 'hump/spike' in the line went away. We switched that out for a wi-fi secondary tv box instead of the hardwired one.

Yesterday had no problems at all.  Today, my wife (works from home) said she's had to disconnect it twice. Only new variable is that my son is home from my in-laws now.  I have him and my daughter BOTH on Chromebooks and BOTH on Roku TVs.

Wife just checked the modem Event Log and this was our recent stuff, stil has T3 errors (see examples below).

Is this still potentially a modem issue/something with Xfinity, or maybe just network congestion? She also just noticed the modem is set to central time (i'm translating/relaying over chat) and we are Eastern, is that an issue?

CRITICAL (3)   Started Unicast Maintenance Ranging - No Response recieved - T3 time-out; CM-MAC=08:36:c9:37:eb:50;CMTS-MAC=00:f3:c8:05:e5:5d;CM-QOS=1/1;CM-VER=3.1

WARNING(5) Dynamic Range Window violation

WARNING(5) RNG-RSP CCAP Commanded Power Exceeds Value Corresponding to the Top of the DRW;CM-MAC=08:36:c9:37:eb:50;CMTS-MAC=00:fe:c8:05:e5:5d;CM-QOS=1.1;CM-VER=3.1;

CRITICAL(3) No Ranging Response recieved-T3 time-out;MAC=08:36:c9:37:eb:50;CMTS-MAC=00:f3:c8:05:e5:5d;CM-QOS=1/1;CM-VER=3.1