Nokia 5800 hard reset

as a phone technician would already know the name hard reset, reformat the phone without flashing, and does not require a good tool box and repair computers, making it very easy and cheap for no cost at all, like in the days of nokia nokia WD2 many successful the hard reset because of damage software, like the picture above shows, or how to do the hard resset on nokia 5800, how to do that is like the nokia WD2, may be useful