PSP 3000 brightness setting is "locked"

[Nightmare-Rex]

I was at school with my PSP 3000 and CFW enabler 3.50. I lowered the clock speed to 10/20 (the lowest speed) and turned it into sleep mode for all the way until lunch. it was acting wired even when I restored the clock setting. so I restarted it (cold boot) and then tried to change the brightness and couldn't it was locked at the same brightness. I've tried CPU speed, restoring default settings (FLASH1) and plugging it in. I also tried changing it from POPS and the screen would shut off and eventual the PSP would shut off completely. if I keep attempting to change the brightness the screen will shut off. The only thing that I know of I haven't tried is Installing 5.03 over 5.03 but that may brick it. is there a fix to this problem? i've found other peaple experienced this problem and the fixed it via updateing. it seems home and note button turns off the screen WTF this is for full hacked PSPs.