Default Tablet RockChip rk2928sdk Bricked

well, i got it bricked after i edited the build.prop
i just changed thigs like device name and model, some thing else i dont remember, but was just name things and when i reboot it it just staid in the
bootlop.
my tablet is chinise, says pyrus electronics when starting and i investigate that is a RockChip and the tablet says that is model rk2928sdk.
some help would be fine: D