Already CFW, switching FW back and forth?

So i have 3.90 M33-3 on my slim. If say i wanted to go back to 3.71, would i have to pandora again (because it just says i have the more current FW and dont need to "update") Is there a special CFW ability or app that can do that?

Also, i have a phat psp that i put to 1.50 w/ pandora. Can i backup the flash0 and NAND for each CFW i upgrade to and just copy that over to go back and forth from FWs that i have had (hope that wasnt too confusing) or will that just brick going from nand 3.52 m33 back to 1.50 (for example)

I think there's a program you can use to flash back to 1.50 and then you can upgrade to whatever firmware you want from there. I can't remember what its called, but no, I'm pretty sure you don't have to Pandora again.

but its a slim. Cant go back to 1.50. I just dont want to have to make a new MMS and pandora all over. Seems like i always get a partial brick the first time then its works the second time. But its scary when it bricks. lol

but its a slim. Cant go back to 1.50. I just dont want to have to make a new MMS and pandora all over. Seems like i always get a partial brick the first time then its works the second time. But its scary when it bricks. lol

what do you mean you always get a partial brick the first time? when you try going to OFW or CFW?

no i got 3.90 m33-3 and staying CFW, just want to downgrade to 3.71 m33 or around there. seems like every time i try to make MMs it messes up the first time. Seems im accident prone. I like to experiment and learn new stuff, but sometimes it doesnt work.