If you are looking for a "Zero C" update (for region freedom or drive unlocking), check these reputable firmware repositories:
This comprehensive technical guide outlines exactly what these updates do, how to download the correct configuration file, and the step-by-step methods to execute a successful system flash without bricking your hardware. Understanding Sony Blu-ray Update Files download sony blu ray zero c upd
site. Installing firmware from unverified sources can "brick" your device (render it permanently unusable). for a specific Sony Blu-ray model? Blu-ray Disc Player Firmware Update | Sony USA If you are looking for a "Zero C"
Sony does not label files as "zero c upd." You must match your device’s model number. download sony blu ray zero c upd
Select OK to allow the player to search Sony's servers.