Here is the developer perspective from the PCSX2 team:
If you have an SCPH-90006 with the v2.30 BIOS, you aren't completely locked out of homebrew. Community developers have created newer exploits: Fortuna / Funtuna: scph90006+bios+new
If you have the "new" BIOS:
The represents the absolute final evolution of the PlayStation 2 hardware, specifically the region-locked model for Hong Kong and Southeast Asia . For collectors and modders, this "new" slim model is notorious for its internal redesign and a revised BIOS that fundamentally changed the landscape of PS2 homebrew. The BIOS Revision (The "8C" Threshold) The most critical aspect of the SCPH-90006 Here is the developer perspective from the PCSX2
Units manufactured from mid-2008 onwards (date code 8C and later ) have a BIOS that patches out the exploit used by standard FreeMcBoot. For these "v2.30" consoles, you must use alternatives like OpenTuna or FUNtuna to enable homebrew. Modding and Regional Info The BIOS Revision (The "8C" Threshold) The most
The SCPH90006 is a PS2 console model released by Sony in 2001. It is one of the most popular and enduring models of the PS2, known for its sleek design, robust build quality, and impressive game library. The BIOS, on the other hand, is a crucial component of the PS2's firmware, responsible for controlling the console's basic functions, such as booting, hardware management, and compatibility with games and peripherals.