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,
Install or use custom firmware on any 6.39 PSP [PSP, PSP Slim, PSP 3000, PSP Go] | Digiex
4 Ways to Upgrade Your PSP Firmware - wikiHow
GitHub - Klozz/PSP_Pro_customfirmware: Source code of PSP custom firmware PRO
Fix Corrupted Data and Recover Files from PSP Memory Stick - EaseUS
How To Update Any PSP To Official 6.61 In 2018! - YouTube
PSP: First hacks for the new Firmware 6.61 - PRO CFW & Downgrader updated! - Wololo.net
PSP Ultimate Database Game Pro - Apps on Google Play