The PS4 stores its previous firmware version in a backup slot on the Syscon chip. By using a Raspberry Pi Pico
To understand why downgrading is difficult, you must understand how the PS4 file system works. downgrade ps4 903 to 900 fix
Here is the brutal truth: Sony’s bootloader (the part that checks your firmware before booting) is designed to prevent exactly this scenario. However, all is not lost. This article details every single possible method to revert from 9.03 to 9.00—from impossible myths to expensive, high-risk hardware solutions. The PS4 stores its previous firmware version in
now supports versions up to 11.00. You may not even need to downgrade to 9.00 anymore to enjoy homebrew. Check your previous version: If you are certain your previous version was 9.00, look into the Modded Warfare guides on Syscon Reverting. However, all is not lost