CM400 High Speed DOCSIS 3.0 Cable Modem(CM400)

[RStranger]

I have a pressing issue that i cannot figure out what is going on. Here is the Modems info - CM400 High Speed DOCSIS 3.0 Cable Modem(CM400).

I have used this modem for a few years on Spectrums Network to be precise. Now i have a different ISP (COX) and for some reason, the modem cannot be seen on Cox network. Cox technician believes that, it has something to do with Spectrum. That is locking the modem. Any help from you guys, will be appreaciated. Since i do not understand why the same modem, won't work on Cox network.

Contacted Support and they could not assist me since i am out of waranty. Which is stupid to me, that as a company. they cannot assist users using their products unless you pay them. No more netgear products for me.

Other than that, any help on this matter would be appreciated.

[FURRYe38]

I would contact Spectrum to see if there was any kind of FW they put on this modem that would lock the modem to be used only to there ISP service. You may need to take it to a spectrum office to have someone look at it. ISP usually don't lock out user owned modems. I have heard odd things though with spectrum. 

Has a factory reset been performed on the modem. Press the reset button for 15 seconds then release. 

Mfrs only warrenty items for a certain time frame. Been like this for a while now. Though there are the forums. Hopefully we can help. 

@vkdelta 

[RStranger]

Spectrum denies performing/installing any firmware that would restrict the modem to be used on another ISP. Yea did a full reset and nothing changes. 

Sad that netgear support cannot get involved in this. Greedy 

[FURRYe38]

Might contact NG support and see what can be done. ISPs will deny anything. 

@vkdelta