Original post by: Jennychan ,
This happens on a regular basis when an esd strap isnt used, my theory is a static build up in the phone through handling. The fix is easy... disconnect the battery, remove all lcd connectors (prox sensor,backplate (where applicable) and lcd connectors. while the battery and connectors are still disconnected hold the power button for 20 seconds and release it. (this drains any static in the system). Finally connect all connectors for the lcd and reconnect the battery. If the lcd is in working order it should power on once again.