iPhone 3GS stuck on white apple logo wont turn on HELP!

Ok so i have a iphone 3gs that ranodmly stopped charging about a week ago so i got the charging dock connector replaced and now it will charge but its stuck on a black screen with the apple logo and doesnt change, its tethered jailbroken so i have to run redsnow on my computer with iphone connected to turn it fully on but its completely dead and it charges a little bit then goes to the apple logo and nothing else happens (doesnt have enough battery for me to do the reboot with redsnow to turn it on) someone please help me ive tryed holding the top corner button and home button but nothing happens!!!!!