Some work, some don’t. You must check the "Date Code."
Disclaimer: This feature is for educational and entertainment purposes. Modifying your PS3 violates Sony’s TOS, voids your warranty, and can permanently destroy your console. how to downgrade ps3 firmware 4.89 to 4.88
However, if your console is already running custom firmware (CFW) or has specific hardware compatibility, downgrading is possible but complex, risky, and requires specific tools. Some work, some don’t
Silas stared at the glowing monitor, the blue light etching deep lines into his tired face. It was 3:00 AM. On his desk sat a relic of a bygone era: a thick, piano-black PlayStation 3 "Fat" model voids your warranty