After many failure, I Bought a safe from Costco, it has hole, an

bought a timer for the power, so it is triple control..  It has worked for 2 year....

Put in safe, so the kid can not re start the modern or use default

With timer, so it cut the power at the time we set, usually 2 AM :-(

Also,  I have a linksys router upstair to control their wifi time for the kid....    

It is 4 level control...  LOL