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Forum Discussion
CM1150V Downlink Light Flashing
My CM-1150V Cable Modem has in issue where the downlink light starts flashing, but everything is working correctly. The modem status shows no issues.
When this happens, I've received two CM-STATUS messages, both for channel 48: CM-STATUS Event type code 20, and Event type code 22. Documentation for these events (Cable labs doc) show event 20 is Next Codeword Pointer (NCP) Profile Failure, and event 22 is NCP Profile Recovery.
I believe that event 22 should stop the downlink light from flashing, but it isn't.
Can Netgear confirm that this is the case? My CM-1150V is using firmware version V2.02.04.
Thanks.
16 Replies
Post the entire logs back here plus the cable connections page. That helps more than a single error.
If there's any spliters, attenuators, or amplifiers in line, remove them. Also check for any damage, kinks, bad/cheap connectors, or extended run with the coax cable.
Here's a screenshot of the error log. The CM-STATUS 16 and 24 messages don't start the downlink light flashing.
One other data point: The downlink light *stops* flashing when I receive CM-STATUS 23 and 22 messages.
I do have a splitter in the line, but cannot remove it.
MadDog97 wrote:Here's a screenshot of the error log. The CM-STATUS 16 and 24 messages don't start the downlink light flashing.
One other data point: The downlink light *stops* flashing when I receive CM-STATUS 23 and 22 messages.
I do have a splitter in the line, but cannot remove it. ---Sure you can. Its for testing. If you remove it and the issue goes away, the splitter was the problem. I'd recommend moving the modem to where the coax enters the home anyway.
And did you have the cable connections page? that helps to compare to the logs.
but as FURRYe38 said, you'd probably need to have the ISP check the line. It just helps to know why you're having them check the lines when you call.
Have the ISP check the signal and line quality UP to the modem.
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.Has a power OFF of the modem for 1 minute then back on change the LED behavior?
Try a factory reset as well...
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-Modems/m-p/1530376#M12853I usually just reboot the modem to clear the flashing light.
Xfinity is totally worthless. Their answer is to reset my wireless router.
FURRYe38 wrote:Has a power OFF of the modem for 1 minute then back on change the LED behavior?
Try a factory reset as well...
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.Turning off the modem will clear the flashing downlink light. However, the downlink light will start flashing again in a day or two. :-(
I have a coax splitter between my TIVO box and CM1150V cable modem. I did try bypasing it and connect the coax cable directly to the CM1150V cable modem. Sadly, it did not solve the flashing problem. :-(
According to the CM1150V modem status, my downstream power for all the 32 channels are around +1dBmV and SNR around 37dB. The 4 upstream channels power are around 43dBmV. Both within the recommended DOCIS 3.1 modem specification.
I believe that it's a firmware issue since my internet connection (around the 900Mbps from speedtest.net) and phone line are fine.
Something to contact the ISP about as well. IF they claim the signal is good, then I would contact NG support. Would be nothing else that can be done here in the forums.
