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,
Tutorial: Installing Infinity - 6.61 Permanent Patch for LME & PRO CFW - YouTube
Custom Firmware with PRO | ReviveToday
PSP Custom Firmware Guide For All Models 2023 - pspunk
PSP 6.61 Custom Firmware Install on any PSP - PSP, PSP Slim, PSP 3000, PSP Go & E1000 | Page 8 | Digiex