Release: Infinity 2.0 – Enables Permanent 6.6x Custom Firmware for all PSPs! - Wololo.net
I tried installing 6.61 PRO C2 and infinity v2.0.3 on my psp 3001 (following the instructions on the CFW guide of this subreddit) but it just shows corrupted data when I disconnect,
Easy Mod For Any PSP/ PSP Go / PSP Street 6.61 CFW Permanent In Just 8 minutes - YouTube
How to install custom firmware on PSP - Easy 2021 (version 6.60) - YouTube