ok, I know it seems odd that I want to go to sonys FW, but the psp isnt mine. I downgraded my friends TA-082 psp to 1.5 then put 3.03 oe-c on it and he liked it till he bought a new game and tried to update the FW on it and it wont let him, he gets (DADADA) and he gave it to me saying make it well. so here I am, everything so far has failed so what I want to do is just go to 1.5 then it should work getting to something else by updating from a disk. I want to get this done as easy as possible and going to custom FW is NOT AN OPTION...for some messed up reason he doesnt want more custom FW on it. if somebody could help that would be great.

I dont think he can go back to regular firmware. if he wants to play his game youll have to convince him to upgrade to a newer custom fw

I don't think you can go back to higher Sony firmwares after downgrading TA-082/TA-086 PSPs.
To allow the downgrade, some keys are changed in the idstorage (or something) and unless you change them back (which I don't think there's an app for at the moment), it will brick when you try and upgrade to higher Sony firmwares.
I would recommend upgrading his PSP to either 3.40 OE-A or 3.52 M33 (both are newer custom firmwares) so that he can play the newer games.
Tell him it would brick (be permanently broken) if you tried to downgrade to 1.50 then update past a certain firmware (maybe 2.71 I'm not sure).