Hi,when a phone does not come on, it is either the battery of the phone is dead,
might need to be charge or replaced with another battery.

you can use another battery to test if it is the battery the fault.

The other thing to check is if the phone memory is weak and may need to be restored
back the phone memory.
will need to be flashed.
if too weak to power up the phone all application you downloaded on the phone has
VIRUS and has affected the phone memory.


First Charge the battery for longer hours before using another battery to confirm
if the battery cell is the problem.

If not battery, in think you will have to flash the phone memory for it to come back to life.
You can use the link below to know about how to flash the phone.

hubpages.com/hub/How-to-Flash-your-cell-phone

and

(unlocktotalk.com/UnlockCodeInstructions.htm),


Take care.