My lumia 520 will not factory reset, but none work,

[WPCentral Question]

I have tried the methods on the Microsoft site and they don't work
My son has forgotten his passcode so I need to reset the phone but it just will not reset
What can I do?

 

[Harrie-S]

See this youtube video how to do the hard reset with buttons but be sure the phone is (fully) charged.
If the battery level is to low the hard reset my not be started.
Another method is to login on The Smartphone Reinvented Around You | Windows Phone (United States)
There you can also send a "hard reset" instruction to your phone but this only works if this is enabled in the phone setting under "Find my phone".