Here is what I have to work with:
MMC - Made with Rains or with Catb50 Teams
PSP Slim 2001 Black (Just bought) with 5.02 Firmware
XP Pro PC - Even attempted to run as admin
Now, I stick in the MMC and then stick in the battery, green light black screen, no side lights.
Do the same holding L, same effect
Insert Battery first, same effect
Punt across living room, same effect