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,
PlayStation Guide
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PSP 6.61 Infinity Hybrid Firmware by Davee, LME & PRO CFW Patch | PSXHAX - PSXHACKS
How to Mod Any PSP on Firmware 6.61 or Lower! - Infinity 2.0 Permanent CFW دیدئو dideo