: Use software tools to modify the "slot" indicators in the Syscon dump, tricking the console into thinking 9.00 is the active version.
How to Revert the PS4 to a Previous Firmware (Full Tutorial) downgrade ps4 903 to 900 fix
If you have already reinstalled 9.03 (e.g., after a hard drive replacement), the 9.00 slot may have been overwritten, making a revert impossible. Preparation: Essential Tools : Use software tools to modify the "slot"
Users often ask: "If I put my old 9.00 hard drive into my 9.03 console, will it work?" The kernel on the motherboard checks the HDD version on boot. It will force a format or freeze at the "Cannot start the PS4" screen. after a hard drive replacement)