CM1000V2 modem cannot connect computer

[NeilU]

CM1000v2 is connected to Optimum cable and Orbi 04 mesh. 

I am getting increasing frequency where internet drops completely even though the modem shows signal. If I hit the restart on the modem it quickly has full signal (I have 200G service but get about 220 on Wi-Fi regularly)

I tried to see if the modem is actually outputting direct signal by plugging my computer directly to modem ethernet BUT I get NO internet signal to the computer. I checked the connection by hooking the same cable to an ethernet port on the Router and I get connection fine. 

This is also disturbing since I could not log into the modem directly (I can through the router)

Will a reset on either or both help? 

[FURRYe38]

What Firmware version is currently loaded?
Please post a copy and paste of the modems connection status and event log page.
https://kb.netgear.com/30007/How-do-I-obtain-the-cable-connection-information-from-a-NETGEAR-cable-m...
https://kb.netgear.com/30008/How-do-I-view-or-clear-the-event-logs-on-my-NETGEAR-cable-modem-or-mode...

Be sure your using a good quality LAN cable between the modem and router. CAT6 is recommended. 
What is the brand and model of the host wifi router connected to the modem?

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. 
Start with removing any amplifiers, signal attenuators, or splitters from the coax.
From there check the line for kinks, damage, moisture in the line.
Check the connectors for improperly made ends, foil touching the copper coax line, loose connections, bad/old/cheap connectors, or corroded connections. Replace them if you do.
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...
https://kb.netgear.com/24311/Power-level-guidelines-for-a-NETGEAR-cable-modem-router
https://www.duckware.com/tech/solving-intermittent-cable-modem-issues.html

[Kitsap]

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@NeilU wrote:

CM1000v2 is connected to Optimum cable and Orbi 04 mesh. 

I am getting increasing frequency where internet drops completely even though the modem shows signal. If I hit the restart on the modem it quickly has full signal (I have 200G service but get about 220 on Wi-Fi regularly)

I tried to see if the modem is actually outputting direct signal by plugging my computer directly to modem ethernet BUT I get NO internet signal to the computer. I checked the connection by hooking the same cable to an ethernet port on the Router and I get connection fine. 

This is also disturbing since I could not log into the modem directly (I can through the router)

Will a reset on either or both help? 

---

You are trying to make things happen too quickly.  To connect your computer directly to the modem, start by powering down your modem (pull the cord) and power down your computer.  Wait a few minutes and disconnect the Ethernet cord before you power up your modem.  Give your modem ample time to go through the boot process and connect with your ISP.  One of the last indicators you will see illuminate is for your phone connections.  Now connect the Ethernet cable to your computer and boot the operating system.  It can take several minutes (I have seen up to 20) for your ISP to release the previously assigned router IP address and assign a new one to your computer.

When you are done, you may have to repeat the sequence when you put your router back in the network.

[NeilU]

Ouch

What I was hoping was I could segregate the issue of whether the internet signal was actually getting through the modem. That would explain why I could not just bypass the connection to the router to see if I am getting real thru-put into the router. 

The modem usually would to show internet signal was strong when it has gone down which again is a question of whether it is the modem or the router. Unfortunately I haven't tried restarting just the router in the past - I keep restarting the modem and that causes the router to also to go through a reboot. And since the only time I get to check this out is when I get a crash I can't just check things out at will. 

Would resetting either or both devices help in the future?

[FURRYe38]

Has a power off for 1 minute then back ON with the ISP modem and router been performed since last update?
Be sure to restart your network in this sequence:
Turn off and unplug modem.
Turn off router and computers.
Plug in and turn on modem. Wait 2 minutes for it to connect.
Turn on the router and wait 2 minutes for it to connect.
Turn on computers and rest of network.

Please give feedback to the questions presented as well...

[plemans]

Next time it goes down, log into the modem through the router and get a screensnip of the cable connections page and event logs. That'll show us connection back to the isp. 

I'd recommend a screensnip as they're easier to read. Many copy paste and its a pita to go through

[NeilU]

The Firmware is V1.01.03

The log and status pages are quite a bit - 

Here is a screen shot for one of the pages. Not sure which is most useful. 

Right now we have too much ZOOMING going on in the house for me to do some of these restarts. 

I did find an older router I can hook up if I get a crash again to see if I can still get signal through the modem. (an older Netgear, not a mesh)

I can try what has been suggested for doing a better restart for both modem and router and will do those when I can work when everybody is free from internet

[plemans]

Your power levels or out of spec (high) and you're getting non locked channels. 

Start with removing any amplifiers from the coax.
From there check the line for kinks, damage, moisture in the line.
Check the connectors for improperly made ends, foil touching the copper coax line, loose connections, bad/old/cheap connectors, or corroded connections. Replace them if you do.
If you can, simply connect the modem right where the coax comes into the home. This prevents wiring in the home from being the issue. And some ISP’s charge if the wiring issue is in the home. So this helps prevent this.

You might try adding in a triple splitter or signal attenuator to bring the power level down within spec. Just use a good quality one. 

[FURRYe38]

https://kb.netgear.com/24311/Power-level-guidelines-for-a-NETGEAR-cable-modem-router

Can you post the Events Log page as well? 

https://kb.netgear.com/30008/How-do-I-view-or-clear-the-event-logs-on-my-NETGEAR-cable-modem-or-mode...

[NeilU]

Here is the events page

I am curious about what constitutes high signal level. 

There is one splitter on the cable when it comes into the house since one line use to go to a TV which I do not use. So the modem gets the main line coming in (after that one splitter that the ISP did install)

Nothing else attached to the line other than a connector box to extend the line. 

[plemans]

Your logs are full of errors to. 

Your line should get checked based off the logs/connections page. 

You're signal should be between -7.5dbmv and 7.5dbmv. You're above that. And with errors in the logs and non connected channels, its indicating an issue. So you can do a few things to try to correct it.

I'd actually pull out your double splitter and put in a triple or quad to see if it gets the signal down a bit. If it doesn't help the quality, then the ISP needs to check it. 

[NeilU]

I recognized that yesterday when I finally went to see how to log into the device. BUT I have no clue how to evaluate this. Fascinating how we are so caught up with AI and Chatgpt when this is 30+ year old technology that drives us all crazy. 

And still with everyone saying it isn't their problem it is a different device or connection. Was true in the 70's and still is. 

So Optimum (we were on Cablevision before they got absorbed into Optimum) says they can't do much to check my modem from their side since it is not Their Version of ARRIS Modem that would be leased. And if I want them to check inside it becomes a big charge. 

I assume you are referring to the Power column. Some channels are ok but others are not. What do I make of different channels and how to tell if they are causing problems.

I have to say that as long as the system is up I do not have any problems. I am signed up for 200MB service but on wifi with the ORBI I am getting continual 230MB download and about 10 upload (its cable not fibre). 

[plemans]

here's a good guide for power levels. 

https://pickmymodem.com/signal-levels-docsis-3-03-1-cable-modem/

[NeilU]

That is useful to see. 

You suggested that I add some interference on my end by adding splitters-(are you suggesting just adding a splitter at a time inline does it?)

but shouldn't they be lowering the power level at the source 

Is this something they can do without entering my unit - they can look at my modem online and know it is connected but I don't know whether they can tell the strength from the central servers - especially to look at the channels

How can I tell what the channels are doing? Are they all important - some are in the recommended level and others nearer maximum

[plemans]

The problem is you can't see all the channels. there's quite a range of them and a certain set of them might be fine. And then the CMTS changes what channels your modem is on and they might have interference. So you can only do the best with what you have. 

It used to be they had all the connections set with just a certain power and they used signal attenuators to make sure your home fell within that range. Not sure if they now have digital control of that but you can do a little yourself. 

My home has the power coming in right around 12-13dbmv. It was to hot and caused quite a few errors. So I added a 4x splitter and capped off the ends on the unused ones. Now my power is in spec and I don't have any errors showing in the logs or cable connections page.  The 4x splitter basically acts as a signal attenuator. The attenuator is the way to go but I happened to have the 4x sitting around and it worked fine. 

[NeilU]

I have to go through my boxes in the garage. I probably have several 2 or 3 port splitters that I could strap together and then see whether there is a change in the power levels. 

Should I assume that doing a reset to the modem would not do anything to any of this. 

What about the router? 

[plemans]

If the issue is coming from the modem, resetting/rebooting it might help temporarily as it can put it on different channels that might not have interference. but its not a long term fix. Its a bandaid. 

Careful with stringing mulitple's together as each junction is a chance for a bad connector/poor connector or even bad splitter that makes things worse. 

[NeilU]

So what becomes a long term fix if the ISP does not cooperate

[plemans]

If its still dropping, rent a modem from the ISP. 

I've had to rent one for a month or 2 to prove to the isp that their line was causing the issue. 

they fight tooth/nail to not have to fix issues until proven its their equipment. 

And who knows, maybe it is the modem and something internal is causing the issue. 

It isn't unheard of and is hard to distinguish the difference from an internal fault to a line issue

[NeilU]

I had done some checking to find out what about their units which is when I was also told they would only reach into their rented version of Arris. But it has definitely been on my radar. 

You have been very helpful in getting me back into troubleshooting mode (and digging into the hardware). A last (maybe) question. You mention that you are only seeing a part of the number of channels. The list shows a total of 32 (which makes sense in binary) and 28 are download.  

But The Aquire Downsteam channel has a frequency 585 MH which is the same as only one channel - 25 which has a power level of 8.5 which is just in the acceptable. Can I assume that this is the only channel that is active in download since the others are all at different frequencies - what then are all the other channels for and does it matter that they are at much higher power?

[plemans]

They're all used. Which is why a couple bad channels can create issues when the rest are fine. 

[NeilU]

I will leave it at this for now and will see what happens as I start some experimenting.

Thank you for your help

[NeilU]

I just added a 3 way splitter next to the modem and WOW - the main channel is down to 0.5 and none are above 5.5. 

[plemans]

Except now you have a ton of errors/uncorrectables. Which is just as bad/worse as getting the power in the right zone. 

[NeilU]

Whoops.  Didn't see that, just looked at the power. 

So I guess I should probably revert back. Hmm. Before there were practically no errors. 

Oh boy.