To be clear: there is no "one-click" software update file that can downgrade a PS4 from version 10.00 to an earlier firmware like 9.00. Sony’s security system uses "fuses" and specific code signatures that prevent the console from installing an older OS over a newer one. If you find a website claiming you can just download a "downgrade.pup" file to your USB drive and click "install," it is likely a scam or malware. How a Real Downgrade Works
Solder a teensy or Raspberry Pi to the Syscon chip and the NOR flash. ps4 tool downgrade v100 verified
A verified downgrade is a complex hardware process, not a simple software trick. It relies on a method known as "Reverting." Every PS4 has two slots for firmware on its flash memory: the current active version and the previous version you updated from. To access the previous version, you must: Open the console to access the motherboard. To be clear: there is no "one-click" software