Need g928t 5.0.2 firmware

Hello, I am trying to imei repair g928t on 5.1.1 but keep getting eror 7.7.8 wit z3x box. I hear if i downgrade to 5.0.2 it will work.. I cannot find g928t stock 5.0.2 download link anywhere

Can anyone share with me g928t 5.0.2 download firmware please

thanks in advance!