Hello
For fullflash a50 first u need freia+datacable
fullflash
*#06# >> info , to see sw version (if is 10 or above u need testpoint)
(if you can't see sw version,just connect it with freia and if "boot file is not accepted" then do testpoint)
Testpoint is a short circuit between a little circle near the left end of the pcb
,near button 1 and ground.Don't cut anything ! ! !
After flash don't forget to undone testpoint ! ! ! Failure to do so will affect standby time (less standby time because power loss).
after fullflash remember to rewrite original IMEI from back sticker
Good luck