Sometimes on a dead phone you have to hold the power button for a long time. Mine would vibrate but not turn on. but after a USB port and Battery change it worked. If you don’t feel the vibrate from the power button hold then you may have a broken power button $2.50. You can send me the phone and I will try to revive it. $50 not including parts.
It’s a great phone and worth it if your strapped for cash.