on my 3g, if i pressed down SUPER hard on it, it would work sometimes. other times if i pushed down and at a certain angle it'd work too. how comfortable are you at disassembling it? when you crack the screen open, there's 3 cords that need to be taken off in a specific order, then plugged back in in a specific order. at least that's how the 3g was, i imagine the 3gs would be pretty much the same way