Help! I changed the magsafe port in my mac last nite. Now one row of keys in keyboard stopped working. thing is the mac is near mint condition. the 5, T, G, B keys no longer work. EDIT: FN key not working too, maybe other but will find out as use machine more. my password has two 5s in it so cannot even login without external keyboard. Can get new keyboard from ebay but. they not screwed in they glued in I read on ifixit. I cannot afford a new machine and this one if near mint the case not turning yellow yet. And rubber base not peeled. How hard is it to replace keyboard? Anyone done it?