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,
Chronoswitch Downgrader ya es compatible con el firmware 6.61 de PSP
4 formas de actualizar el PSP - wikiHow
PSP 6.61 Infinity Hybrid Firmware by Davee, LME & PRO CFW Patch | PSXHAX - PSXHACKS