error 9 after hard drop

im working on a phone that gets error 9 after a hard drop. the phone is just stuck on apple logo. it only pulls .5 amp with usb amp meter. i checked 1v8 and 3v0 nand power lines as well as 2 of the 3 lines that typically short in the bb_cpu. (cant access the 3rd without removing cpu shield) all seems good. when powered with dc power supply it only pulls .07 amps. i tried reballing the nand and still exact same symptoms. tried to find a short on a low power rail with freeze spray but nothings showing its face. just looking for some ideas