If you have flashed the incorrect firmware file to your stb and the stb still boots then there is no reason why you cannot flash the correct file to your stb assuming of course that you have it or can obtain it. If the stb does not boot then the only other two courses of action open to you which are, to jtag the stb, assuming you have jtag connections on the mother board or can locate them alternatively bin the stb and buy something that has proper support.