-- I discovered that the ethernet port on his brand new...

[mdk]

@rmikeyt --  I discovered that the ethernet port on his brand new monster PC doesn't work!

Huh? Previously, you said that your child was disconnecting the Ethernet cable that connected to the WAN port on the secondary router, and connecting that cable into the Ethernet port on the computer, to bypass the secondary router.

Reboot the child's computer, and try again. Also, check the comments from @g-idk 

[rmikeyt]

No, I was trying to anticipate his next move. 

[heglinb]

We did this for a while and it fried the modem sadly. 

[Jenschafer]

Did you ever find a solution I'm having the same problem with my granddaughter I'm not sure how she is doing it but she does have an iphone and manages to have wifi all night even though I turn it off