3.55 can be downgraded. There are instructions. You will have to look around to figure out which downgrade hex to flash, and then check out the thread regarding downgrading to 3.55 (browse around)
Originally Posted by Milz
Consider the alternative: Updating to KMEAW Custom 3.55 firmware. You are already partly there.
Understand that the concern here is that you said your friend updated, but you didn't say it was only to 3.55. 3.56 is BAD NEWS - attempting to go into service mode on 3.56 or above will BRICK YOUR CONSOLE.
P.S.: Smack your "friend" upside the head, then never, ever loan out your PS3 again.
Working hard on UberCFW, incorporating NTFS, sub-free NetFlix and Blockbuster, PSN cheat system with built-in swearbot and MAC-spoofing, Adding MKV, RAM and BIK movie support, and Xbox360 emu*.
*not really. Get a life, newbs...
My YouTube channel: http://www.youtube.com/user/BenJeremy