Ascend Y300 Doesnt boot

[H3roChr1s]

Hi,i changed build.prop using ROM Toolbox Pro,to play incompatible games,now I copied back the original build.prop,then i restarted,but the phone doesnt boot,it shows huawei logo then it goes black.Tried full factory reset,wiping cache,but it still doesnt work.My phone is rooted,but rooted without unlocking the bootloader.Please help me!Any help is appreciated.