I did a battery replacement for my SP 4 and an earphone connector replacement. I had to remove the LEFT speaker, and there are speaker wires and also a ribbon connector which connects to a tiny ZIF connector on the motherboard. The ribbon connects the ON-OFF button, and the volume UP-DOWN buttons. I killed the ZIF connector lever, so I glued it back on and it looked a little crooked but not much, and now I can not turn my unit on, although the battery charges. I am in the process of ordering a ten dollar left speaker which looks like it has the buttons and ribbon cable. There is a similar UNUSED ZIF connector on the board a few cm to the right that is supposed to connect to some kind of camera that doesn't exist on my SP 4. Mine doesn't have a fan, either. I am planning to remove the entire old, glued ZIF connector and speaker, and replacing it with the new spkr/button assy, and unused ZIF connector. Have to get out my operating microscope and SMT soldering tools to do it. Should be fun. I don't see any fried fuse resistors on the board, and they check ok with the VOM.