CM500-100NAS Upstream Channels Partial Service

[jannamore]

SETUP

As the subject references, my modem indicates that it is only locking onto one upstream channel (see logs below). Current setup:

• Netgear CM500 modem
  
• Google WiFi (1 primary, 2 non-primary points)
• Performance Pro Internet plan (200 down / 5 up)
• 20+ devices
• DL/UL speeds are for the most part fine (both on wireless and plugged directly into modem)
• No splitters between wall cable drop and modem

ISSUE/LOGS

I am not suffering connectivity issues other than one specific issue. Any time I am on a video call/audio call over the Internet, the other party consistently complains about my video or audio quality. This happens across various devices (tablet, PC, phone, etc.), with various A/V setups (built in webcam, peripheral webcam, wired/wireless headphones, etc.).

My modem's upstream light is a blinking green (indicating partial upstream service), and here are the logs: 

Modem Log 
Event Log 

TROUBLESHOOTING ATTEMPTS

I've power cycled the modem and router, remote reset the modem (via xFinity dashboard and phone call), factory reset the Google WiFi, and that's about the extent of my technical knowledge. ISP will be sending out a technician tomorrow to check outside line connection, and/or install or replace Point-of-Entry filter to boosts signal levels. 

Is there anything else I can tell the technician to check based on the above logs and information? Thank you! 

[vkdelta · Accepted solution]

thank for you such a clear description and formatting. I wish other users could be like you!

your Signal levels are bad.

for downstream: TONS of Uncorrectables

for upstream: you got partial service and just ONE UPSTREAM channel that is hanging on last leg. It could die anytime

I strongly suggest you to call your ISP and ask them to fix the line.

If you have any splitters or bad cables, remove it

If you have other outlets in your home, try those if they are better.

Who is your ISP?

Is this old home or new build?

[FURRYe38]

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. 

[jannamore]

No splitters that I can see and I replaced the coax between wall and modem with new 3ft. RG6 coax. Technician coming out tomorrow to check wiring and install point of entry filter.

[vkdelta · Accepted solution]

thank for you such a clear description and formatting. I wish other users could be like you!

your Signal levels are bad.

for downstream: TONS of Uncorrectables

for upstream: you got partial service and just ONE UPSTREAM channel that is hanging on last leg. It could die anytime

I strongly suggest you to call your ISP and ask them to fix the line.

If you have any splitters or bad cables, remove it

If you have other outlets in your home, try those if they are better.

Who is your ISP?

Is this old home or new build?

[vkdelta]

also you will see in the event log, modem tried each of the other upstream 16 times and failed to get response from headend. thats why it went into partial service.

[jannamore]

@vkdelta- thanks for your comments about my post. I just wanted to make the problem as clear as I could. 

I have some updates, and some new logs, and a potentially new issue. 

Updates

• ISP sent out a technician this morning to "...check outside line connection, installation or replacement of Point-of-Entry filter to boosts signal levels."
• I don't know what the technician actually did, but I can confirm that all four upstream channels are now locking. 
• Purely anecdotal, but people are not complaining about my A/V quality today. 

New Issue? 

• Power levels still seem high on the upstream channels, and there is a new issue with large amounts of correctables/uncorrectables in the downstream channels. 

New Logs 

• New Modem Log 
• New Event Log 

[jannamore]

realized I forgot to answer some of your questions @vkdelta - home is old, built in early mid 1900s, wired for cable only, no fiber available; ISP = XFINITY. 

[vkdelta]

if you see your Channel 6, 10, 11, 12 . there are significantly large amount of uncorrectables, so that means more noise.

also, US power is quite high.

are there disconnections?

are you getting good speeds?

this is not a good signal level (SNR) and US power is too high.