NIghthawk CM1150V Drops Dial Tone

[factman]

Our ancient RCA 4-line phones had been working okay with the CM1150V voice modem, but they really needed replacing after 20 years and us down to just two phone lines these days. Frustratingly, the 2-line system I found and really like, Panasonic's KX-TG9581 Corded/Cordless Phone with "link-to-cell" (a feature I have not activated) keeps losing the dial tone on the personal line which is connected to this Nighthawk CM1150V voice modem.

Our personal phone line -- the one that loses the dial tone -- is connected to the CM1150V modem. Our business line is connected to a separate Arris voice modem Comcast supplied (and the new phone has worked flawlessly with this modem). The problem is with the Netgear CM1150V.

After a few hours and sometimes after a day or two, the dial tone just disappears from the personal line plugged into the CM1150V. To restore the dial tone, I've ahd to reset the modem via Comcast's site. The Panasonic phone is a DECT6.0 (Digital enhanced cordless Telecommunications 6.0) with Bluetooth. The base unit is connected directly to the modems. I ran into the same problem with a VTech DECT 6.0 system I tried before settling on the Panasonc system.

So I am wondering if the Netgear CM1150V is incompatible with DECT 6.0 phones even though Netgear's site asserts "Your cable telephony modem is compatible with wired phones and cordless DECT (Digital Enhanced Cordless Telecommunication) phones. Your cable telephony modem does not have DECT hardware installed. In order to use your DECT phone with your cable telephony modem, you must have a DECT base station." And indeed, it is my DECT base station that is connected via the phone lines to the Netgear CM1150V modem.

I am hoping that somebody in this community may have some clue as to what could be causing the dial tone to simply disappear like this and how to cure the problem.

Thanks for whatever guidance can be provided. 

[factman · Accepted solution]

Solved with a little luck.

After a lot of experimentation, I stumbled upon deep in the new phone's settings, something called "Line Mode." (Initial Settings | Line Select) I've since learned that modern DECT 6.0 phones have this buried deep in their internal phone system menu -- and both phone systems with which I had lost the dial tone were DECT 6.0 systems. The setting for the business phone line that worked was "B." The setting for the personal phone line that was losing the dial tone was set on "A." Long story short, I reset the Line Mode for the personal line to "B" and it has not dropped the dial tone even once in over a week.

Thanks so much for the time and thought you devoted to solving this problem.

[FURRYe38]

Netgear has set up a community forum specifically for the Cable Modem products. Most of the people who watch that forum are more likely to have experience with Cable modems and know how to work it better than those of us who follow this router forum. Might be more likely to find someone who has a solution if the question is posted there:
https://community.netgear.com/t5/Cable-Modems-Routers/bd-p/home-cable-modems-routers

Be sure to have the ISP check the signal on the coax and phone lines up to the modem. 

Be sure the ISP configures the modem for phone services. 

Please use this link to the main forum product list to review and choose where to make your posts. 
https://community.netgear.com/t5/NETGEAR-Forum/ct-p/en-netgear
Thank you.

[factman]

Thanks. I'll post in that forum. 

BTW, the CM1150V had been working just fine as I wrote with my old phone system. Comcast had everything configured properly. It's only with these new phones that the dial tone keeps dropping -- and only from the CM1150V. The business line using Comcast's Arris modem is working just fine. 

[factman · Accepted solution]

Solved with a little luck.

After a lot of experimentation, I stumbled upon deep in the new phone's settings, something called "Line Mode." (Initial Settings | Line Select) I've since learned that modern DECT 6.0 phones have this buried deep in their internal phone system menu -- and both phone systems with which I had lost the dial tone were DECT 6.0 systems. The setting for the business phone line that worked was "B." The setting for the personal phone line that was losing the dial tone was set on "A." Long story short, I reset the Line Mode for the personal line to "B" and it has not dropped the dial tone even once in over a week.

Thanks so much for the time and thought you devoted to solving this problem.

[FURRYe38]

Glad you got it working. Enjoy.