Release: Infinity 2.0 – Enables Permanent 6.6x Custom Firmware for all PSPs! - Wololo.net
How To Downgrade PSP 6.61 To 6.60! (Chronoswitch Downgrader) 2017! - YouTube
Complete Guide to PSP Custom Firmware | ReviveToday
4 Ways to Upgrade Your PSP Firmware - wikiHow
PSVita: Qwikrazor87 releases PSP 6.61 PRO-C f3 & Hello World 3.36FW with ePSP 6.61FW - Hackinformer
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,