Default [Q] Brick and need help

so as i try to get a rom in my phone i just had the bootloader unlock and when i went to adb reboot the phone did not came back to no life no matter what i did. i would sw reboot or recovery reboot and nothing my computer recognizes is at omap and then disapears i have a MetroPCS 769 which is simmilar to T mobile on the phone it states as 760 thanks for the help also i am new to this