it is not recomended to do this my friend; they have different hardware at all; w880 lacks of upper side power button (uses c), light sensor for auto brightness adjust (as k770 does) and led flash... as i saw at their disassembly guides they use the same keypad (speaking about component) but different lcd (as you realized after your first attempt...) it is more likely to continue having problems even after applying patches... reflash your k770 with its original FW and develop the sound by applying a modded acoustics pack (you'll not get walkman player but much better sound) ;)