My phone Just immediately shutdown and doesnt turn on anymore

I tried to charge the phone for hours, the phone temperature was cold and Cant feel any temperature rise and heat from the inside of the phone, tried the hard reset and DFU button combination and it doesnt work. Then i tried to put it on a non genuine charger that makes sound when it plugged in and there is a Repeating sound from the charger like Zzzzzt. Zzzzzt. Tried the same thing w my other iphone and it only sounds like zzzzzzzzzzzz. Maybe someone can help me to diagnose whats wrong with my iphone here;(