Need help:i bricked my zte blade l3 after a firmware crash

i tried all methods posted in all forums and no one worked
1. igot permanently blackscreen no lifesign from my handy
2.recovery or bootloader etc. dont work
if want to connenct the phone on my computer it connect 2 secs later disconnnect ,then connect ,disconnect (it does that all the time i let it connected on the cable.
so thats my problem ,any idea what i can do now,please help me

thank you in advance