i have similar issue with my c5502
phone crashed suddenly and wont open anymore i was on custome rom so my BL was unlocked
i wiped system and flashed the linageos rom again but still wont boot up i get starting sony logo then phone shuts down
i flashed with s1tool same issue
flashed with flashtool both firmwares 5.1.1 and 4.3 and still sony logo and shuts down any ideas ?!