iphone 4 wont restore / stuck in greepois0n black screen

i recently tried to jailbreak my friends iphone 4g with greenPois0n. greenpois0n gave me a error which people usually get when trying to jailbreak a iphone 4.3 or higher with greenpois0n which only jailbreaks 4.2, The Iphone is Now stuck in a black screen that says:

unable to find gbdevlist
unable to find fs_mount
unable to find fs_unmount
unable to find fs_load_file
greenpoi0n initialized

....

I cant get rid of this screen, I have tried to hard-reset the device but it just takes it into DFU mode. i cant get the apple logo or the "connect to itunes" screen to show up,

i have tried tiny umbrella's fix recovery tool, that is the only way i can get out of a pure black screen and into a greenpois0n black screen that i mentioned above.

i tried a number of different things and nothing works, somebody please help me fix my friends iphone?!

Is this a verizon iPhone 4?