c7800 disconnecting often

[khamilton315]

Bought the C7800 Nighthawk in Feburary of 2020 brand new. Everything was great, could not ask for any better performance. Last week I started losing connectivity to it. Xfinity cable internet is up and running fine, no issues, no outages. Now, this problem is getting worse. My devices lose connectivity more frequently, quite frequently, so much we cannont enjoy our normal entertainment. Very annoying. This is how we watch TV and game. Tried contacting support but I am out of my 90 days Technical Support, although I have a year warranty on the product (makes sense, right!? NO!) Horrible customer service. Very disappointed. I've unplugged the router to power cycle. Connection resumes immediately but will go out shortly after. I've rebooted via the genie app, connection resumes immediately but will go shortly thereafter. What am I missing? What might fix this issue to where I am back up and running. Again, This router is 5 months old before I ever had one single problem, it worked flawlessly up until last week. Tips and Tricks are very much welcome. Please help. I have four children and if the internet is down, it's the end of the world.

[khamilton315 · Accepted solution]

The internet has worked flawlessly since the technician arrived. It was definitely on the ISP’s (Comcast/Xfinity) end. Haven’t dropped once in the last two days and performance is better. Definitely check where your power level is on the downstream and the upstream.

Also I believe some of the tweaks Furry had me do helped performance.

Thanks again Furry, appreciate your time.

[FURRYe38]

Is both wired and wireless devices experiencing this? 

What channels are you using? Auto? Try setting manual channel 1, 6 or 11 on 2.4Ghz and any unused channel on 5Ghz.
Any Wifi Neighbors near by? If so, how many?

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. 

[khamilton315]

Yes, both wired and wireless are experiencing this. 

Yes the channel was on Auto and I changed it per your suggestion.

How do you know if a channel is unused to assign it to the 5Ghz?

Yes, it appears I can see three to four neighbors Wifi available. 

Comcast/Xfinity has tried many things on their end and they say everything is good until it drops connection. This happens when I'm actually talking to them and they see it. I do not believe there is any "splitters" used and they are sending a technician Monday to check my lines. 

[khamilton315]

Also Netgear states my upstream power is too low. There are 4 channels locked and they very from 31 to 34.

My downstream power is too high. there are 32 channels locked and they vary from 5's to as high as 8.4

Netgear provided me the proper performance, upstream 45-48 and downstream -7 - +7.

Netgear stated this can only be corrected by the ISP (Xfinity). Called Xfinity and they had no clue what I was talking about and referred me back to Netgear.

[FURRYe38]

Ya, your ISP needs to look at your signal on the line. There playing hard to get/stupid and it's there responsibility on the there side of the fence. I would ask for excalated support or someone else. Modem mfrs can't control any thing on the ISP side of the fence. 

[khamilton315]

Can you refer to message 3 of our thread. I answered most of your questions. I did ask you, how do you know if a channel is "unused" to assign it to the 5Ghz.

[FURRYe38]

Install a wifi analyzer on a pad, apple or android. Check to see who around is using 5ghz channels. 

[khamilton315]

That worked great on finding the channels with less traffic. Much appreciated on that. Also I'm on hold with excalated support. Appreciate that one too. You've been a great help. Appreciate your time and helpfulness. I do not know at this time if it has helped my situation but I feel much better, more educated. Again, Thank you!

[FURRYe38]

Hopefully ISP will get it figured out. 

Good Luck. 

[nrami016]

Hi, do you mind updating this thread if your issue has been resolved? I am on the same boat as you are with the random disconnects from the router... The router is a beast but the disconnection issues are detrimental to the user's experience.

Just making sure that it is not the router before I return it; I received it yesterday and almost immediately I began noticing the random drops from either 5 Ghz or 2.4 Ghz.

Thanks in advance,

Neil

[FURRYe38]

Is both wired and wireless devices experiencing this? 

What channels are you using? Auto? Try setting manual channel 1, 6 or 11 on 2.4Ghz and any unused channel on 5Ghz.
Any Wifi Neighbors near by? If so, how many?

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. 

---

@nrami016 wrote:

Hi, do you mind updating this thread if your issue has been resolved? I am on the same boat as you are with the random disconnects from the router... The router is a beast but the disconnection issues are detrimental to the user's experience.

Just making sure that it is not the router before I return it; I received it yesterday and almost immediately I began noticing the random drops from either 5 Ghz or 2.4 Ghz.

Thanks in advance,

Neil

---

[khamilton315]

No, this has not resolved the issue. Although it is better it has dropped a few times today. I have a technician from my ISP coming tomorrow morning.

[FURRYe38]

Good. Hopefully he can narrow it down where the problem is. Ask him to take a look at the connect status of the modem while he's there too. 

Keep us posted. 

[nrami016]

Furry,

Hi. I'm not sure what happened to my original reply back to you. In any case:

While using the C7800 [firmware V3.01.43], I was using 'Auto'. I did try the suggestions you offered below and I did a channel refresh, which switched to different channels. I did not set things up manually. Also, thanks to you I did learn how crowded the radio field is nearby my house; now I can set the router to a channel that is not crowded.

I proceeded to call Comcast and though I couldn't get my call escalated to 2nd/3rd level, the tech did find that the SNR/Power ranges were a little high for the UP stream (something new I learned).

The tech sent a new router configuration, which did help with the unit auto restarting/rebooting on its own but it did not fix the issue. I then proceeded to remove the splitter between the main cable drop from the pole to the house, and that also helped somewhat but the problem remained.

After many minutes troubleshooting things around, I decided to go back to my old modem C7000v2 to test if actually the coax or the splitter or something else was off.. to my surprise, my old cloncker picked up from where I left it off yesterday and haven't have a reboot/restart/dropped signal issue yet.

The only reason why I tried upgrading to the C7800 was for the added horsepower it brings but I guess something is off with some of these units. Although mine's was bought as a refurb unit (I learned this after the fact, no excuses), I've seen people who have bought these new from Netgear and also are experiencing the drop out/disconnect/restart issues as well.

Thank you for the troubleshooting guide and for your help.

Best regards,
Neil

---

@FURRYe38 wrote:

Is both wired and wireless devices experiencing this? 

What channels are you using? Auto? Try setting manual channel 1, 6 or 11 on 2.4Ghz and any unused channel on 5Ghz.
Any Wifi Neighbors near by? If so, how many?

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. 

---

---

[khamilton315]

Comcast/Xfinity was here promptly at 8am. They did their outside check and noticed that my downstream power was too high and upstream power too low (He was the first person to actually say those terms and understood that worked for Comcast, which made me feel better that someone knew what they were talking about). They did some work on their end and replaced some lines and I believe replaced my outside box. The downstream power is in the noraml parameters now. The upstream is just slightly lower than the netgear parameters now, but much better than what they were. Their correction raised it from low 30's power to 40's with one 39 but not up to 45-48 where netgear recommends. The technician stated he could not get it any higher than that and that was Comcast normal parameters now.

I will update this later today or tomorrow to let you all know if this corrected my issue of disconnecting service often. 

@nrami016 @FURRYe38 

[FURRYe38]

I recommend returning the C7800 as its a refurb and may have additional problems. Not everyone has problems with the c7800 rebooting. Mine worked well for a long time before taking it off line. 

I recommend that if you want better wifi horse power, keep your C7000, configure it for modem only mode and install a external wifi router. You have more choices and more control over the wifi router than you do with gateway modems.

[khamilton315 · Accepted solution]

The internet has worked flawlessly since the technician arrived. It was definitely on the ISP’s (Comcast/Xfinity) end. Haven’t dropped once in the last two days and performance is better. Definitely check where your power level is on the downstream and the upstream.

Also I believe some of the tweaks Furry had me do helped performance.

Thanks again Furry, appreciate your time.

[FURRYe38]

Glad to hear the ISP got things working better for you. You should be good now. 

Please mark your thread and solved so others will know. 

Enjoy,