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Forum Discussion
CM1200 Modem Dropping Connection
Just recently installed the Netgear CM1200 modem to support the 1G Internet service I upgraded to from my ISP "RCN" here in Pennsylvania. I also have an RAX70 Netgear Nighthawk (also new) attached an...
First I appreciate the help and responses. Still trying to narrow down this issue as I await RCN’s technical team to look into this. So this morning at 6:58am the modem dropped service again. Do the attached Event Logs lead anyone to a possible issue? This techy modem jargon is just Greek to me.
2nd attachment.
Lots of Errors in there. Thats needs to be reviewed and addressed by the ISP/Tech. Have them look at this log and your connection status page. It should be similar to mine:
I've scheduled an RCN Tech to be onsite on Thursday 1/28. Hopefully I'll get some answers about this modem dropping issue (which is still occurring 1-2 times every day) and will let you all know how it goes.
Also have the tech look at the modems UI and watch you speed test as well with a wired PC connected to the modem while he's there.
One other bit of info from RCN. I reached out to them via Twitter and they sent the question about the 32-channels to their technical group. Here's their answer:
"We use whatever channels we need to use to accomplish the needed speed. If pressed, for RCN, we usually shift into OFDM channels after 16, though this can vary."
RCN Technician came by today. He initially checked the signal on the cable in my office to check for errors and all looked good...no issues. He checked the connections outside my home and found the connection at the pole and the connections on either side of the underground cable were 'bad.' He also said there was a splitter on the outside of the home that didn't need to be there. She he replaced all the connections and took out the splitter and he did say that the signal was improved (he said it went from a +2 to a +7 whatever that meant.
He still thinks that, although he fixed some things to bring it up to spec, the issues we're having are equipment related. He said IF it continues to happen, then 99% sure it's the modem. So I'm going to monitor this for a day or two and see what happens.
And regarding the question about the 16 locked channels vs. 32 channels, he said that some ISP's do 32 channels but RCN is different and they do not. As soon as I started to ask about it, he started shaking his head NO (like he knew I what I was going to ask) so it sounds like an RCN-thing. Bottom line is I'm showing ~900M speed on the download side off my router so I'm getting the bandwidth. Guess I don't care if it's 32 or 16 channels....as long as it stays UP and I fix this possible modem issue. We'll see
- Hope it works!
Ok, glad they seem to have got it working better. I guess some ISPs maybe using 16 channels vs 32. If that works for them then I guess it works. Possible there compressing signals into 16 channels. Sounds like it maybe mosty a connection issue since they reported finding bad connections on there side. Also I would chreck the modems FW as well. v1s seem to have more problems. I'm on v2. I believe there is a v3 aswell.
Hope it keeps working.
bcooper27 wrote:RCN Technician came by today. He initially checked the signal on the cable in my office to check for errors and all looked good...no issues. He checked the connections outside my home and found the connection at the pole and the connections on either side of the underground cable were 'bad.' He also said there was a splitter on the outside of the home that didn't need to be there. She he replaced all the connections and took out the splitter and he did say that the signal was improved (he said it went from a +2 to a +7 whatever that meant.
He still thinks that, although he fixed some things to bring it up to spec, the issues we're having are equipment related. He said IF it continues to happen, then 99% sure it's the modem. So I'm going to monitor this for a day or two and see what happens.
And regarding the question about the 16 locked channels vs. 32 channels, he said that some ISP's do 32 channels but RCN is different and they do not. As soon as I started to ask about it, he started shaking his head NO (like he knew I what I was going to ask) so it sounds like an RCN-thing. Bottom line is I'm showing ~900M speed on the download side off my router so I'm getting the bandwidth. Guess I don't care if it's 32 or 16 channels....as long as it stays UP and I fix this possible modem issue. We'll see
So today I took the CM1200 back to Best Buy and told them we've checked everything and the RCN tech even made connection replacements on the cable and sees everything running perfect on their side, but the modem continued to have Internet dropping issues. I told them that after talking with RCN, we figured that if it continued dropping after they made sure everything was fine on the network side, it would HAVE to be equipment issues so I wanted to replace it.
Best Buy swapped it out for another CM1200 and I installed that today about 3:30pm ET. About 10mins ago (10:10pm or so) the new one did the SAME thing. Internet dropped, the download light was flashing again and I had to reboot to get it back up and running. SAME problem. Checking the logs it showed same errors as previously shown in posts above.
I can't believe I had two bad modems. I got them from two different Best Buy stores, not that that makes a difference, but it could. I guess there's a possibility of me getting two bad ones but the odds have to be astronomical. I fully believe there's a config issue of some sort, quite possibly the firmware. Right now the modem shows Firmware version V2.02.05 which I think is the latest. If I had to bet money, this is the issue. So this begs the question, how do I get the modem on a different version to test it out? Is this driven by the ISP RCN?
Again, appreciate the help as I continue trying to troubleshoot this problem. I don't want to give up on the Netgear Modem....I've had good luck with all of my Netgear equipment over the years and I want to exhaust every effort before I throw in the towel.
Its either a ISP signaling, confifguration issue or the ISP needs to update FW as suggested. Two same model modems experiening same problem would not be a modem problem.
bcooper27 wrote:So today I took the CM1200 back to Best Buy and told them we've checked everything and the RCN tech even made connection replacements on the cable and sees everything running perfect on their side, but the modem continued to have Internet dropping issues. I told them that after talking with RCN, we figured that if it continued dropping after they made sure everything was fine on the network side, it would HAVE to be equipment issues so I wanted to replace it.
Best Buy swapped it out for another CM1200 and I installed that today about 3:30pm ET. About 10mins ago (10:10pm or so) the new one did the SAME thing. Internet dropped, the download light was flashing again and I had to reboot to get it back up and running. SAME problem. Checking the logs it showed same errors as previously shown in posts above.
I can't believe I had two bad modems. I got them from two different Best Buy stores, not that that makes a difference, but it could. I guess there's a possibility of me getting two bad ones but the odds have to be astronomical. I fully believe there's a config issue of some sort, quite possibly the firmware. Right now the modem shows Firmware version V2.02.05 which I think is the latest. If I had to bet money, this is the issue. So this begs the question, how do I get the modem on a different version to test it out? Is this driven by the ISP RCN?
Again, appreciate the help as I continue trying to troubleshoot this problem. I don't want to give up on the Netgear Modem....I've had good luck with all of my Netgear equipment over the years and I want to exhaust every effort before I throw in the towel.
this is all very helpful I too am having the same issues with the downstream light constantly blinking. We got his modem back in july of 2020 and everything has been fine until now. I had a tech at the house today and they are trying to say it is the modem. They connected the ISP modem and were able to get the 900speed but once connecting the CM1200 modem back, all sorts of problems. Is it truly concluded that the issue is a bad modem, or the ISP no longer wanting to communicate with the CM1200 modem? Any advice is welcomed as I need to get this back up working with all the zooms required these days from home.
Please post a copy and paste of the modems connection status page.
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#M12853IF it was actually established that the CM1200 wasn't working well, then you'll need to contact NG support and ask about and RMA.
tparker20 wrote:this is all very helpful I too am having the same issues with the downstream light constantly blinking. We got his modem back in july of 2020 and everything has been fine until now. I had a tech at the house today and they are trying to say it is the modem. They connected the ISP modem and were able to get the 900speed but once connecting the CM1200 modem back, all sorts of problems. Is it truly concluded that the issue is a bad modem, or the ISP no longer wanting to communicate with the CM1200 modem? Any advice is welcomed as I need to get this back up working with all the zooms required these days from home.
The frustration dealing with RCN saying their side ws fine and continued drops on the CM1200 (not one, but TWO CM1200's with the same issue) forced me to try a different modem. I fully believe the issue is firmware/software related between RCN's network and the modem, but I don't have time for them to figure it out.
That being said, the other night I went out and purchased an Arris SB8200 (which I believe is the same modem RCN would install if you lease/rent it from them) and it's worked flawlessly for the past week.
I'm a Netgear guy but my patience on these issues just wore thin. I still have my RAX70 Nighthawk on the other end and that works great, but unfortunately we had to go in a different direction on the modem side.
Appreciate everyone's help. Sorry it didn't work out with the CM1200.
FWIW - I also ran into this issue with RCN and the CM1200. Exact issues you noted but I didn't end up bringing a tech back out based on this thread.... so thanks for the time savings! Phone call to RCN indicated they didnt see an issue in their line at all, even tho the modem was down.
Also tested 2 different CM1200s with the same defect, and just bought an ARRIS SURFboard SB8200. Installing in a few days and will report backShame the ISP won't update the FW to help test that out.
Just as a follow up to my earlier Feb post, the switch to the Arris SB8200 was the right move when it came to the issues with our Internet provider RCN. It's worked flawlessly since I installed it, not one issue.
Since this is a Netgear Community, I can't help but also give kudos to the Netgear Nighthawk AX8 RAX70 router that we're using. That has also worked perfectly and we've got excellent connections throughout the entire property. It's a great router.
Good luck with getting your issues fixed.
Im very dissapointed.
Bottom line, Spectrum will not update the firmware. As a customer, I dont care who the problem is. All i know is that I have a top of the line CM1200 sitting in my basement because it is unreliable (clearly due to a firmware issue).
Heres a tip for everyone, dont bother getting a tech to your home 4x, calling spectrum 8x, installing new lines, etc.... at the end of the day--- switch to Spectrum's modem. Itll save you time AND actually be fixed.
Dear Netgear---HELP your customers by reaching out to Spectrum about this MAJOR issue. As of this moment---im not sure ill trust netgear again. You have great products, but ---CLEARLY the CM1200 has an issue with Spectrum services since it is widely reported and a "known issue" (verified ONLY after I had to do some limit setting with Spectrum, who tried to give me the run around).
the very least Netgear could do is awknowledge its a WELL known issue.
Anyone looking to buy the expensive top of the line plastic brick in my basement?NG has acknowledged the problem by fixing the problems in the FW. NG does pass this on to ISPs. However, again, it's up to ISPs to push the FW to modems. And again, some ISPs choose not to do this for user owned modems, such as Spectrum.
Hope you can find someone to buy your modem from you. It's a good modem if it can be updated and work well on a ISP that is willing to support it and push the FW to it.
MisFiTkEv wrote:Im very dissapointed.
Bottom line, Spectrum will not update the firmware. As a customer, I dont care who the problem is. All i know is that I have a top of the line CM1200 sitting in my basement because it is unreliable (clearly due to a firmware issue).
Heres a tip for everyone, dont bother getting a tech to your home 4x, calling spectrum 8x, installing new lines, etc.... at the end of the day--- switch to Spectrum's modem. Itll save you time AND actually be fixed.
Dear Netgear---HELP your customers by reaching out to Spectrum about this MAJOR issue. As of this moment---im not sure ill trust netgear again. You have great products, but ---CLEARLY the CM1200 has an issue with Spectrum services since it is widely reported and a "known issue" (verified ONLY after I had to do some limit setting with Spectrum, who tried to give me the run around).
the very least Netgear could do is awknowledge its a WELL known issue.
Anyone looking to buy the expensive top of the line plastic brick in my basement?Purchased the CM1200 directly from NetGear and recently the downstream channel light begins flashing.
I unplug the power cord and remove the cable feed to the modem or a combination thereof. It eliminates the flashing for a given period and the flashing returns.
Looking at earlier reported issues, I see that there is a comment posted that asks to ensure that no coax cable line splitters in the between the modem and ISP service box. I currrently have a coax line splitter which allows the cable line to feed to my modem.
This problem is a recent issue so why the sudden issue when the splitter has been in place for years and this modem has been inuse for months prior to the current problem with the downstream light flashing.
I upgraded to this modem because my cable provider (Spectrum) notified me that my earlier modem was only compatible with DOCSIS 3.0 and that their requirements are for DOCSIS 3.1 [my connection would fail intermittently].
I have had good experience with NetGear equipment and made the leap to this modem with the hopes it would resolve the DOCSIS compatibility issues, provide me with the latest technology and be steadfast & useful modem for a number of years.
Now this.
Genesan212 Please start your own thread with your complete details. include a screen snip of the cable connections page and the event logs.
