I just installed and activated my new Netgear CM3000 modem but status says connection is poor due to low downstream power. I rebooted several times, checked cable connections for tightness, but nothing has any effect:
Cable Connection
Cancel Apply
Cable Diagnostic
Status: Poor
Action: [Downstream Power Level] Try these actions (Click the Refresh button after each step): 1) Make sure the coaxial cable is tightly connected. 2) Remove any unnecessary splitters. 3) Replace any required splitters. 4) Contact your service provider for troubleshooting help.
CM Status:
Downstream Status:
Downstream Power Level:
Downstream power is poor (-12.8dBmV). The recommended level is between -10dBmV to 10dBmV.
Downstream SNR:
Upstream Status:
Refresh Save Cable Diagnostic Info
Advanced Information
Frequency Start Value
This field below allows you to modify the frequency the cable modem start with its scan during initialization and registration. Enter the new start frequency and restart the cable modem for it to take effect.
Yep. It's too low / out of spec. The upstream power is almost out of spec as well. That can cause random disconnects, spontaneous re-booting of the modem, speed, packet loss, latency problems, and the un-bonding of channels.
Stuff that you can try;
In an effort to try to obtain better connectivity / more wiggle room, check to see if there are any excess/unneeded coax cable splitters in the line leading to the modem that can be eliminated/re-configured. Any splitters that remain should be high quality and cable rated for 5-1002 MHz, bi-directional, and no gold colored garbage from Home Depot, Target, Wal-Mart, etc. Splitters should be swapped with known to be good / new ones to test.
Also check the coax cable for any damage such as cuts, nicks, abrasions, kinks, sharp bends, etc.
If there aren't any unneeded splitters that can be eliminated and if your coax wiring setup can't be reconfigured so that there is a single two-way splitter connected directly off of the drop from the street / pole with one port feeding the modem and the other port feeding the rest of the house/equipment with additional splits as needed and you've checked all the wiring and fittings for integrity and tightness and refresh them by taking them apart then check for and clean off any corrosion / oxidation on the center wire and put them back together again, then perhaps it's best to book a tech visit to investigate and correct.
Thank you so much! Xfinity technician came and checked the signals to the home, which matched what I was seeing. I have no splitters just 1 cable to my house and to inside. Then he checked the feed by the road to my house, that showed the same results. Now he has dispatched a maintenance team to check the main feed to the subdivision. He said the whole subdivision has this out of spec signal. He also was surprised at how I could read these signal levels myself :D. I said yea, that is why I had enough and bought my own modem. I was tired of chatting with Xfinity India regarding the Xfinity modem/router combo telling me "Everything looks good from our side, would you like to save on your internet bill by purchasing mobile phone service from us?"
@ozkayamur Welcome to our community forum and thank you @EG for jumping in with your expert knowledge :). I'm glad the technician was able to refer this to our maintenance team and I'd like to keep an eye on your account so I can check in after the work has been completed.
Please send a direct message by clicking the chat icon in the upper right corner of the page, click on the pen and paper icon, then enter “Xfinity Support” in the “To” section. Please include your name and address and I'll be happy to help.
The maintenance technician finished their work and left, but now this is what the cable diagnostic gives me. Still poor connection, but this time it's flopped to upstream power:
Cable Diagnostic
Status: Poor
Action: [Upstream Power Level] Try these actions (Click the Refresh button after each step): 1) Make sure the coaxial cable is tightly connected. 2) Remove any unnecessary splitters. 3) Replace any required splitters. 4) Contact your service provider for troubleshooting help.
CM Status:
Downstream Status:
Upstream Status:
Refresh Save Cable Diagnostic Info
Advanced Information
Frequency Start Value
This field below allows you to modify the frequency the cable modem start with its scan during initialization and registration. Enter the new start frequency and restart the cable modem for it to take effect.
No, I am not currently having any connection issues, but my modem says it's still not within spec. I did some research and found that attenuator can be installed on my modem coax inlet to bring it to spec. Do you have any recommendations on this solution?
Accepted Solution
EG
Expert
•
105.7K Messages
1 month ago
Yep. It's too low / out of spec. The upstream power is almost out of spec as well. That can cause random disconnects, spontaneous re-booting of the modem, speed, packet loss, latency problems, and the un-bonding of channels.
Stuff that you can try;
In an effort to try to obtain better connectivity / more wiggle room, check to see if there are any excess/unneeded coax cable splitters in the line leading to the modem that can be eliminated/re-configured. Any splitters that remain should be high quality and cable rated for 5-1002 MHz, bi-directional, and no gold colored garbage from Home Depot, Target, Wal-Mart, etc. Splitters should be swapped with known to be good / new ones to test.
Also check the coax cable for any damage such as cuts, nicks, abrasions, kinks, sharp bends, etc.
If there aren't any unneeded splitters that can be eliminated and if your coax wiring setup can't be reconfigured so that there is a single two-way splitter connected directly off of the drop from the street / pole with one port feeding the modem and the other port feeding the rest of the house/equipment with additional splits as needed and you've checked all the wiring and fittings for integrity and tightness and refresh them by taking them apart then check for and clean off any corrosion / oxidation on the center wire and put them back together again, then perhaps it's best to book a tech visit to investigate and correct.
Good luck with it !
1
EG
Expert
•
105.7K Messages
1 month ago
My pleasure ! Good luck !
0
XfinityEmilyB
Official Employee
•
1.6K Messages
1 month ago
@ozkayamur Welcome to our community forum and thank you @EG for jumping in with your expert knowledge :). I'm glad the technician was able to refer this to our maintenance team and I'd like to keep an eye on your account so I can check in after the work has been completed.
Please send a direct message by clicking the chat icon in the upper right corner of the page, click on the pen and paper icon, then enter “Xfinity Support” in the “To” section. Please include your name and address and I'll be happy to help.
0
EG
Expert
•
105.7K Messages
1 month ago
It's my pleasure @XfinityEmilyB ! 😊
0
0
ozkayamur
5 Messages
1 month ago
The maintenance technician finished their work and left, but now this is what the cable diagnostic gives me. Still poor connection, but this time it's flopped to upstream power:
[Upstream Power Level]
Try these actions (Click the Refresh button after each step):
1) Make sure the coaxial cable is tightly connected.
2) Remove any unnecessary splitters.
3) Replace any required splitters.
4) Contact your service provider for troubleshooting help.
Number Range
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EG
Expert
•
105.7K Messages
1 month ago
That may not be too low. Are you actually experiencing any connectivity problems ? If not, don't sweat it.
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0
EG
Expert
•
105.7K Messages
1 month ago
If it ain't broke, don't fix it. Ignore that message. Arris is wrong.
1