CM500-100nas amber upstream light - available channels vs number of channels shown

[SteveUSA1]

I've tried searching this and haven't seen a direct question or answer to this question, only references. If missed it somewhere else I apologize.

My modem is a CM500-100NAS and my ISP is Spectrum. We have had the modem for several years now and has always been great but lately there has been some serious buffering and stuttering while streaming movies/tv. I made some changes to a seperate router settings that have improved it a lot but during my investigation I noticed that where the modem always had steady green lights the upstream indicator was now amber. Logging into the modem shows that only 1 upstream channel is locked.

I know that the ISP controls the config file and only 1 upstream may be needed, depending on the plan but my question is this - regardless of how many upstream channels are bonded or allowed to bond, how many should be displayed? This modem has 4 upstream but only 1 is showing. If all are supposed to be showing, is this an indication that the modem is about to die and needs replacement?

 Something else I noticed in the channel display today that wasn't there the last couple of days is the high amount of uncorrectables on two of the downstream channels.

[FURRYe38 · Accepted solution]

I would ask the ISP how many channels they using for the UP. If they say more than one then possible the modem maybe faulty. 
Might ask them as well if there is any FW available from them they could push. 

Have the ISP check the signals and line up tot the modem to be sure. 

Check all cables, connections and coax connectors. Some times connectors can be bad, go bad or not properly made in the first place. 

[FURRYe38]

Correct and Un-correct's should be mostly near zero.

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-Mod...

Have the ISP check power levels as well:
https://kb.netgear.com/24311/Power-level-guidelines-for-a-NETGEAR-cable-modem-router?article=24311
https://www.duckware.com/tech/solving-intermittent-cable-modem-issues.html
https://highspeed.tips/docsis-events/

https://community.netgear.com/t5/Cable-Modems-Routers/One-upstream-channel-locked-amber-light/m-p/21...

[SteveUSA1]

@FURRYe38 I appreciate the fast response and suggestions. I also saw those during my searching and will definately do them after work however, I think you overlooked my question:

How many, in total, upstream channels should be seen in the status screen? IE: If there are 4 channels and only 1 bonded, should I see only the 1 bonded channel or should I see 3 unbonded channels and 1 bonded. 

Based on screenshots from other posts, unbonded channels are listed along with the bonded channels but I want to confirm if that is always the case or not.

[SteveUSA1]

Here is my view of the status page:

Downstream Bonded Channels
Channel Lock Status Modulation Channel ID Frequency Power SNR Correctables Uncorrectables
1 Locked QAM256 10 669000000 Hz -4.9 dBmV 40.1 dB 2 0
2 Locked QAM256 1 615000000 Hz -5.2 dBmV 39.9 dB 4 0
3 Locked QAM256 2 621000000 Hz -5.4 dBmV 39.7 dB 5 0
4 Locked QAM256 3 627000000 Hz -5.6 dBmV 39.7 dB 3 0
5 Locked QAM256 4 633000000 Hz -5.1 dBmV 39.9 dB 5 0
6 Locked QAM256 5 639000000 Hz -5.4 dBmV 39.8 dB 1 0
7 Locked QAM256 6 645000000 Hz -4.8 dBmV 40.1 dB 7 0
8 Locked QAM256 7 651000000 Hz -5.5 dBmV 39.8 dB 4 0
9 Locked QAM256 8 657000000 Hz -4.8 dBmV 40.1 dB 11 0
10 Locked QAM256 9 663000000 Hz -5.2 dBmV 40 dB 7 0
11 Locked QAM256 11 675000000 Hz -5.2 dBmV 39.7 dB 4892 15964
12 Locked QAM256 12 681000000 Hz -5.2 dBmV 40 dB 5077 22375
13 Locked QAM256 13 687000000 Hz -5 dBmV 40.1 dB 5 0
14 Locked QAM256 14 693000000 Hz -5.3 dBmV 40 dB 5 0
15 Locked QAM256 15 699000000 Hz -4.6 dBmV 40.2 dB 2 0
16 Locked QAM256 16 705000000 Hz -4.9 dBmV 40.1 dB 11 0

Upstream Bonded Channels
Channel Lock Status US Channel Type Channel ID Symbol Rate Frequency Power
1 Locked ATDMA 1 5120 Ksym/sec 17600000 Hz 57 dBmV

Current System Time:Thu Feb 03 18:17:15 2022

[FURRYe38]

That depends on the speed package you get from your ISP and what yoru ISP supports. Something to ask them about. 

High speeds like 1Gb on the down uses 31 and 32 channels for the down on my ISP service. My 50Mb up link, 4 channels are locked in on my ISP service. 

---

@SteveUSA1 wrote:

@FURRYe38 I appreciate the fast response and suggestions. I also saw those during my searching and will definately do them after work however, I think you overlooked my question:

How many, in total, upstream channels should be seen in the status screen? IE: If there are 4 channels and only 1 bonded, should I see only the 1 bonded channel or should I see 3 unbonded channels and 1 bonded. 

Based on screenshots from other posts, unbonded channels are listed along with the bonded channels but I want to confirm if that is always the case or not.

---

[SteveUSA1]

@FURRYe38  I'm not trying to be dense but I feel like I am not clarifying the question enough. I'm not asking how many should be used to support my ISP package. 

How many of the upstream channels should be visible in the status display?

Regardless of their status, even if they are not required, even if they are not necessary and even if they are not used by the ISP. Should all 4 still be listed when viewing the status?

For instance, in this link you gave me:

https://community.netgear.com/t5/Cable-Modems-Routers/One-upstream-channel-locked-amber-light/m-p/21...

the screenshot of the solved message ( 4 of 5 ) shows 4 locked channels and 4 not locked channels. The unlocked are not necessary or used but are still showing as available.

[FURRYe38]

From what the spec sheet says this model modem supports 16 down and 4 up so these should be in the display UI:

https://www.downloads.netgear.com/files/GDC/datasheet/en/CM500.pdf

[SteveUSA1]

Ok cool. Then would that indicate an issue with the actual modem and not with the ISP or the coax or the signal? The troubleshooting portion of the manual shows nothing about channels not showing in the UI and mine only shows 1 upstream channel in the display UI. That said, if after a factory reset the other 3 channels are not visible in the display UI, would that indicate that the modem itself is going out?

[FURRYe38 · Accepted solution]

I would ask the ISP how many channels they using for the UP. If they say more than one then possible the modem maybe faulty. 
Might ask them as well if there is any FW available from them they could push. 

Have the ISP check the signals and line up tot the modem to be sure. 

Check all cables, connections and coax connectors. Some times connectors can be bad, go bad or not properly made in the first place.