I made the mistake of updating to 3.72 HX1 right after it was released thinking it would make some more of my ps1 games compatible (RE2) only after i updated i found out about 3.71 M33 3. Any way to downgrade it with out a pandora as i dont have one or know how to make one?
Not into PSP myself anymore, but I'd imagine you'd just need a Recovery File (versus trying to 'downgrade' via Pandora) to get back... maybe someone who uses PSP CFW can reply with more specific help though. Good Luck!
As far as I know on PSP, you can only downgrade using Pandora, however if there is such a Recovery File as PS3News has mentioned, then hopefully someone can help you out and in the mean time you can do a few searches to see what you can find. If you do need any help in making a Pandora, then post back on here & I can help you out as its very simple (as there are lots of "all in one" packages about!)
Sorry I could not respond sooner. No, you don't have to buy a new battery, as once you have fixed your PSP you can convert the battery back to normal again. As long as you have made a backup of the flash (EEPROM) of the battery, then you will be fine. Good luck!
TheRF is right. and the easiest way to downgrade is using the pandora battery, it even gives the option to install 1.5 or DA's m33 fw. but since you're already at custom fw you could just use the recovery menu to downgrade to 1.5.. hold R during the psp's cold bootup