Do not just search for "SCPH5502.BIN." Add the version number. Many no-intro databases have multiple revisions of the European BIOS. There is a and a v3.0b . For the SCPH-5502, you want the original v3.0, not the later 7002 v3.0. Use the console code SCPH-5502 as your primary filter.
This is the BIOS revision used in the PAL (European) "PS One" style consoles and later original grey boxes. It is widely considered the most stable version for PAL games. Do not just search for "SCPH5502
For preservation and emulation purposes, the SCPH5502.bin file is crucial for running European releases at their correct speed (50Hz) and with proper region handling. Unlike earlier models, the v3.0 revision had improved copy protection checks and different boot logic. you want the original v3.0