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Forum Discussion
Connected, Online, but ALL Devices Offline? CBK752/CBR750 Cable Modem w/ Spectrum
Hi all,
I’ve been back and forth with Netgear CS and Spectrum for the last couple weeks to figure out why the Orbi WiFi 6 model CBR750 (CBK752-100NAS) I purchased to replace the Spectrum provided solutions has been seemingly “phantom” breaking nearly every day. In short, despite numerous Netgear calls and Spectrum technician appointments resulting in good signals and even new coaxial cables, it has been going “offline” despite our combined efforts. Currently the third time it has been re-provisioned on the latest firmware.
What keeps happening is that while most of the day the Orbi cable modem works very well, when the problem arises, neither the Orbi status lights nor the ring light at the bottom indicate anything wrong. Checking the router settings page from wired or wireless computers indicates a good cable connection with no issues. The worst part is that it does not resolve itself unless manually rebooted by reseating the power cable or rebooted from the Orbi app within the network. Even with Anywhere Connect, when it goes “offline” the app cannot even find the Orbi so I'm powerless to reboot it unless I am home which is rather disheartening if you rely on a WiFi camery system for security.
The only thing that I have to show for this are cable modem’s event logs that don’t always coincide with the internet outages. Errors such as loss of sync, CM-STATUS event type code 5, T3 timeouts, and every now and then the following two: “mismatch between calculated value for P1.6hi compared to CCAP provided value” and “commanded power in excess of 6dB below the value corresponding to the top of the DRW.”
Has anyone heard of something similar? For the time being I’ll be picking up a Spectrum router to compare with as I believe it’s a problem with the Orbi rather than the ISP given how extensively they’ve redone the cabling and checked everything up to the Orbi.
11 Replies
What Firmware version is currently loaded?
Please post a copy and paste of the modems connection status page.
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 then back ON.
https://community.netgear.com/t5/Cable-Modems-Routers/General-info-and-Troubleshooting-for-Cable-Modems/m-p/1530376#M12853What is the size of your home? Sq Ft?
What is the distance between the router and 📡 satellite(s)? 30 feet or more is recommended in between RBR and RBS📡 to begin with depending upon building materials when wirelessly connected.What channels are you using? Auto? Try setting manual channel 1, 6 or 11 on 2.4Ghz and 40 to 48 channel on 5Ghz.
Any Wifi Neighbors near by? If so, how many?Thanks again for redirecting me to the proper section!
- Firmware on CBR750 is currently on the most up-to-date V4.6.3.6_2.0.48, satellite RBS750 on up-to-date V4.6.3.16.
- I have tried replacing my ISP's / Spectrum's provided coaxial cables with my own RG6 quad-shielded coaxials with and without the Spectrum provided splitter to split phone and internet as well as shutting the Orbi cable modem off for up to 2 minutes.
- Home is approximately ~2000 square feet with both cable modem and satellite positioned on the second floor to beam down from an open loft and kitchen area at approximately 20 feet apart from each other.
- I have tried a few different configurations with wifi channels according to Netgear Technical Support including adjusting MTU values (from 1500 to 1475 to 1472 to 1492 and now back to 1475), increasing 2.4GHz and 5GHz CTR/RTS Thresholds to their maximum values of 2347, and trying Google's 8.8.8.8/8.8.4.4 and Cloudflare's 1.1.1.1/1.0.0.1 IPv4 DNS settings.
- Spectrum has replaced an old coaxial cable and disconnected any unused coaxial cables connected to an amplifier in our attic and provided two dedicated lines for power to the amplifier and internet/phone which is then split accordingly. According to the few techs and supervisor that have stopped by, signals are great and everything up to the Orbi cable modem is excellent. As mentioned before, the Orbi cable modem is now on its third reprovisioning.
- There are generally 2-3 wifi neighbors.
Screenshot of the up/downstream bonded channels attached as in-post photo doesn't seem to work:
