Originally posted by qwerew
Thanks for your help!
"X:/PS3/UPDATE/PS3UPDAT.PUP"
Where X: is your usb stick/external HD. Has to be Fat32 Filesystem formatted.
Go from Custom 3.55 to Official 3.55 then Format/Rebuild the harddrive using the recovery menu, then boot the playstation and go to system update and update to Official 3.56.