This is the most practical advice. A used PS4 on firmware 9.00 or lower sells for a premium ($250–350). A PS4 on 10.50 is worth the standard used price ($150–200). Sell your 10.50 console and use the proceeds to buy a confirmed 9.00 unit from eBay, Facebook Marketplace, or r/PS4Homebrew.
The PS4 motherboard stores two firmware versions at any given time: the (current version) and the inactive slot (the version you had immediately before your last update). ps4 downgrade 10.50 to 9.00
Each time you update to a new major firmware (e.g., 9.00 → 10.50), the PS4 burns efuses on the Southbridge chip. When booting, the firmware checks the fuse count. If the installed firmware is older than the fuse count, the system refuses to boot. This is the most practical advice
: This process requires advanced soldering skills. You must dump data from the NOR and Syscon chips using a microcontroller (like a Teensy or Raspberry Pi Pico) and patch the system to swap the active slots. Why People Want 9.00 Sell your 10
Stores the previous version installed before the last update.
