Iphone External Screen I Was Using My IPhone 3GS And It Died And Now It Won't Turn On. I Have Tried Everything Including Hard Reset?

I was using my iPhone 3GS and it died and now it won't turn on. I have tried everything including hard reset? - iphone external screen

Ok, I spoke at length with my iPhone this week, and I was in the car and was dying when I have to wear my external battery. It was about 15%. Restarts for no reason, but not on the Apple logo screen and then he died. I have tried everything to revive it again, let it load for over an hour I tried resetting, tried removing the SIM card, tried to connect to my computer and not the thing where u hold the key restoration "Home", etc. .. , Wanted to connect it to my computer and restart. Nothing works. I am currently abroad and can not apply to an Apple Store or Apple, but will return Monday. Please help me, I need GPS in my phone, because if I screwed: (