My psp 2000 not unbricking please help?

hey guys i have psp 2000 slim i had psp 5.50 promethuse and by mistake i formatted flash0 and now it is fully bricked.when i turn it on green light appears and shut offs automatically.my friend has pandora battery and mms and i have tried to unbrick it(with all those stuffs,inserting mms holding L and putting pandora battery) but than yelllow light at help side of psp appears for few seconds but nothing on screen,it just shuts off.i have tested it in my friend's psp but it works perffect in his psp. but i dont know why my psp is not reading mms and pandora battery. i used rain mms maker for 4.01 please help me guys i need ur help for turing it to cfw screen so i can unbrick it.