Answer to "What is Tos02 on the board?"I scrutinized the images and believe the area around the 'TOS02' marking has nothing to do with a SIM card for a few reasons: The pads at the lower right (if they are indeed solder pads) are 10 in number when a SIM has 6 contacts and it doesn't match up with any SMD SIM trays I could locate after a cursory search online. The SIM 'notch' at the upper right is one of two curved parallel markings related to what was probably an antenna cable. The silkscreening on the other side of the board mirrors these marks. It's possible an earlier revision had a wired antenna attached to the Panasonic WiFi daughterboard. It now appears that the antenna is part of the PCB, see traces near the corner. The daughterboard would have to be removed to confirm this, but the top antenna connector appears unused.