Verdict: 1/5 Stars – Does Not Exist as Advertised. Avoid scams.
If you are searching for a "PS4 downgrade tool" to revert your console from firmware 9.00+ back to 5.05 or 6.72 (for homebrew or jailbreak purposes), stop here. After extensive research and testing of multiple claimed "solutions," I can confirm: The Core Problem Sony uses efuses (one-time programmable fuses) on the PS4 motherboard. When you update the system software, the update blows a specific set of these fuses. The bootloader checks the fuse count against the firmware version. If the fuse count is higher than what the older firmware expects, the console will refuse to boot—permanently.
Verdict: 1/5 Stars – Does Not Exist as Advertised. Avoid scams.
If you are searching for a "PS4 downgrade tool" to revert your console from firmware 9.00+ back to 5.05 or 6.72 (for homebrew or jailbreak purposes), stop here. After extensive research and testing of multiple claimed "solutions," I can confirm: The Core Problem Sony uses efuses (one-time programmable fuses) on the PS4 motherboard. When you update the system software, the update blows a specific set of these fuses. The bootloader checks the fuse count against the firmware version. If the fuse count is higher than what the older firmware expects, the console will refuse to boot—permanently.