Files for startup and shutdown you will find in /tpa/preset/system/settings/and here you have: shutdown_image_semc, splash, startup_image_semc, startup_sound_semc.mid
So if your phone is CID52 you can access to file system with XS++ and tutorial is here
XS++ 3.1 Guide-Flashing, Customizing, Recovering - Top Sony Forums just look part 5. "uploading files via FSX"




