Some years ago, using my PSP 3001A, I wanted to have those "Pandora CFW for 5.03 FW" exclusive to PSP models 1000 & 2000, So i wanted to downgrade my System and then run one of those CFW's, naturally, since they were exclusive to those models, so i downgraded to 5.03 and obviously i couldn't amount to much, I couldn't update also because the system couldn't recognize the firmware, and therefore i was on tight spot, until i came with an idea.
This "Franken PSP CFW" couldn't do anything BUT, launching a specific kind of file repeatedly, so i downloaded a 6.20 FW, I launched and prayed that i could recover my broken PSP... It worked!, then i installed my PRO 6.20 CFW and everything was back to normal, now, why did i wanted such a thing?, back then those CFW's were the shit, they had almost 100% compatibility with any homebrew, but they were exclusive to those PSP models, and now, the newer CFW's are obviously better, specially the Infinity PRO CFW, but that experience was years ago, so that.