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CM2000 keeps losing downstream connection.

trob787
Aspirant

CM2000 keeps losing downstream connection.

Hi all,

 

Having a sporadic issue with my new Netgear CM2000 modem. I keep losing the downstream connection, or so it seems, the LED blinks and I have no connectivity. Rebooting the modem fixes the issue. I have a Orbi RBR850 for the router with one satellite. I have attached a picture of the logs for today when it happened and downstream and upstream. I have RCN for internet ~200Mb down 20 up. Any help is appreciated thanks!

 

netgear modem log 11-25-20.pngdownstream channels.pngupstream channels.pngdown-up OFDM.png

Message 1 of 18
FURRYe38
Guru

Re: CM2000 keeps losing downstream connection.

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-Mod...

Message 2 of 18
plemans
Guru

Re: CM2000 keeps losing downstream connection.

Photos can take a while because a moderator has to approve them. And unless there's a new reply, its rare for us to re-check posts. 
So you can click on "choose file" and attach the photos (each one an individual post) and we can view them. Otherwise it could be a while. 

But @FURRYe38 advice is sound as well

Message 3 of 18
trob787
Aspirant

Re: CM2000 keeps losing downstream connection.


@plemans wrote:

Photos can take a while because a moderator has to approve them. And unless there's a new reply, its rare for us to re-check posts. 
So you can click on "choose file" and attach the photos (each one an individual post) and we can view them. Otherwise it could be a while. 

But @FURRYe38 advice is sound as well



Thanks! Will attach as separate posts.

Message 4 of 18
trob787
Aspirant

Re: CM2000 keeps losing downstream connection.

 
Message 5 of 18
trob787
Aspirant

Re: CM2000 keeps losing downstream connection.

 
Message 6 of 18
trob787
Aspirant

Re: CM2000 keeps losing downstream connection.

 
Message 7 of 18
plemans
Guru

Re: CM2000 keeps losing downstream connection.

Doesn't look like you have any channels locked after channel 16 on the downstream?
I'd have your isp check the line. Like @FURRYe38 says, check the line for kinks, damage, poor/cheap connectors, loose connectors, extended runs. Preferably, directly connect the coax from where it enters the home to the modem. if there's a splitter, remove it and check the connections. 

Message 8 of 18
trob787
Aspirant

Re: CM2000 keeps losing downstream connection.


@FURRYe38 wrote:

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-Mod...



Was trying to avoid a call to RCN, I'm not the primary account holder but will do I first suspected that it was a provisioning issue. I repurposed a RG6 run to be the modem. Will check the splitter locations. Will also try the power down for a minute.

Thanks for the responses!

Message 9 of 18
trob787
Aspirant

Re: CM2000 keeps losing downstream connection.


@plemans wrote:

Doesn't look like you have any channels locked after channel 16 on the downstream?
I'd have your isp check the line. Like @FURRYe38 says, check the line for kinks, damage, poor/cheap connectors, loose connectors, extended runs. Preferably, directly connect the coax from where it enters the home to the modem. if there's a splitter, remove it and check the connections. 



Yes. No channels locked after 16 down. I don't have gig service, so I don't think I need them? Current service level is 155 down but I get 200 accross speedtest sites. Will check the splitter locations and for damage thanks.

Message 10 of 18
plemans
Guru

Re: CM2000 keeps losing downstream connection.

Even if you don't need them, they still usually lock. 

It "usually" indicates a line or provisioning issue. 

Message 11 of 18
trob787
Aspirant

Re: CM2000 keeps losing downstream connection.


@plemans wrote:

Even if you don't need them, they still usually lock. 

It "usually" indicates a line or provisioning issue. 


Good to know!

Message 12 of 18
nbob
Aspirant

Re: CM2000 keeps losing downstream connection.

@trob787 I am experiencing the same with RCN. I have gone through reprovisioning the modem twice. RCN is coming this week to check on wiring. Did you have any luck getting this resolved? I still only have 16 channels locked. 

Message 13 of 18
trob787
Aspirant

Re: CM2000 keeps losing downstream connection.

Hi there @nbob,

No resolution for me. I kept losing downstream sporatically. I tried another of the same modem and same issue. Had a tech out to check signal on all the exterior wires, they checked out and he replaced all the connectors. I have switched back to the Motorola surfboard (that only locks 4 channels down) that I was upgrading from. I'm giving it a week to see if I lose connection at all. 

I also read elsewhere that this modem and the cm1000 I think, just don't work well with RCN.

 

Hope that helps some,

-Tim

Message 14 of 18
nbob
Aspirant

Re: CM2000 keeps losing downstream connection.

I might have to go with an a different modem. Can you provide the resources where it said this modem does not work well with RCN? 

Message 15 of 18
trob787
Aspirant

Re: CM2000 keeps losing downstream connection.

@nbob this is the thread that I interpreted that from. 
https://community.netgear.com/t5/Cable-Modems-Routers/CM1200-Modem-Dropping-Connection/m-p/2044053
Not an exact quote but I had a similar experience.

Message 16 of 18
BRansom1978
Aspirant

Re: CM2000 keeps losing downstream connection.

So yes, both the CM1200 and CM2000 no longer work with RCN (at least in PA) following the most recent firmware update. I have 4 neighbors, and we all have the modem notes above, and all have the exact same issues with the downstream channels not locking. RCN does not provide support for the modems and really pushes the consumer to use their equipment. The modem will work for 2-6 hour increments, but then requires resetting. Very frustrating to buy this high-end equipment only for it to not work, and then NETGEAR points to RCN, and RCN blames NETGEAR. Both sides point to a firmware problem, no body takes action and the poor consumer takes it in pocketbook. Go figure.
Model: CM1200|Nighthawk Multi-Gig Speed Cable Modem
Message 17 of 18
FURRYe38
Guru

Re: CM2000 keeps losing downstream connection.

Can try a different modem brand or model and see if the problem continues. 

 

What happens when the DOCSIS spec allows the ISPs to support pushing FW updates to users owned modems, or NOT. For these ISPs, if users are having problems with user bought modems and the ISP will not fully support it or places blame, then we would recommend to users to avoid all the hassles with these certain ISP, use the ISPs equipement or find a different ISP service, if available. Apparrently ISPs have been burned on historical accounts, pushing untested or not fully tested FW to user owned modems which broke the modem. Thus the user claimed that there equipement was now broke due to the ISP pushing bad FW and the ISP had to replace the modem at there cost and expence. So ISP stopped pushing FW and developed a policy for user owned modems. So some ISPs throws this out at users. So if something isn't working right at the users modem. Sorry, ISPs are hands off. There only responsible for the line and signal up to the modem and thats it. 

 

Some bigger ISPs have there own testing processes in which modem mfrs like NG will send them FW updates. Those ISP will test the new FW out before pushing to users owned modems or push on a as needed basis. 

Message 18 of 18
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