C7800 - Cannot connect to 2.4Ghz anymore.

[braddman]

Firmware Version

V6.01.07

So this is super annoying. I cannot connect to the 2.4ghz wifi anymore with my phone. 5ghz works fine. A lot of devices are still connected to 2.4 but I just cannot connect. Tried rebooting, etc. No effect. The error on the phone is COULDN'T AUTHENTICATE CONNECTION. Same with my echo shows. They all say INCORRECT PASSWORD. And of course there's no more tech support for this $400 cable modem. 

Computer says CAN'T CONNECT TO THIS NETWORK. Rebooted the modem over and over. 

[plemans]

1. you say some devices are connected to the 2.4gh? how many? which ones connect? which ones dont?

2. did you try changing the password? remove any special characters or spaces from the ssid/password?

3. when did it start? Was anything changed when it started?

[braddman]

Looks like the firmware was updated by Comcast. Recently started in the last couple days. Yeah changing the password has no effect, it does the same thing.

[plemans]

have you tried a simple factory reset and reinstall?

Push and hold reset for 7-15 seconds while its powered on

[braddman]

I have not. I saw a post about someone else that has me thinking. The firmware jumped from 3.xx to 6.xx and the guy is saying Comcasf pushed the wrong firmware to these, from a different device. No firmware jumps 3 majors. I Called clueless Comcast and the lady sat there and tried to tell me Comcast doesn't push the firmware out. I literally hung up on her.

[plemans]

Try the reset. Maybe the firmware change was enough to mess up the old settings. 

[braddman]

Ok thank you

[braddman]

OK so a factory reset didn't work. Sometimes if I reboot the modem I can connect once on my phone but after that it says COULDN'T AUTHENTICATE CONNECTION. The computer still won't connect it says UNABLE TO CONNECT TO THIS NETWORK. Any ideas?

[plemans]

Its still broadcasting during this? you can see the ssid? 

Just not connect/use it? 

Is it only on noe device? more than 1 device? 

do wired devices have issues?

[braddman]

Broadcast stays up and it's only the 2.4ghz band. Echo shows also say incorrect password. And it is correct.

[plemans]

Is it only 1 device having issues? 

Multiple devices? 

Do some work and not others? 

[braddman]

Multiple. Phone won't connect, echos say invalid password. But yet there's probably 20 other devices connected..

[plemans]

Are you using any special characters/spaces in the password or ssid? 

If so, change it. 

Also, try setting your speed on the 2.4ghz from 1000mbps down a notch.

[braddman]

No special characters. It's the same password it's been since I got the modem. I'll try that but the speed always worked fine..works once after a reboot then never again will it reconnect.

[braddman]

Tried lowering the speed to 433. Worked once. After I disconnected and reconneced couldn't authenticate connection. 

[plemans]

Try changing it to something with no spaces. 

Avoid spaces/special characters in the password as well

[braddman]

I think I figured out what's happening. I found in another thread that Netgear gives no fs about bugs. Apparently you can't connect more than 20 devices to 2.4 and this starts happening and they never fixed it. I connected a few of my smart home devices to my wifi extender instead and I'm able to connect now. It utterly blows my mind that this has not been fixed.

[FURRYe38]

One reason it may not be fix is that there maybe a HW limitation on how many devices you can connect to one radio at a time. You can't just connect unlimited amounts of devices to one WiFi radio. There are some limtations. Not all wifi can handle large qualities of devices. Been like this for years. Nature of the beast. 

One thing you might do is connect a wifi extender, like you did, this helps off load some of the wifi devices to a different wifi source to share the band width. 

[braddman]

There's a hard limit but it's not 20. It's supposed to be supposed to be 32 per band..

[FURRYe38]

Also depends on what your devices are doing as well. One device doesn't just take up 1 connection, there are many per device.