I used to have custom firmware 5.50 GEN-B (If I remember correctly), and I have accidentally updated using the official updater, making my PSP 6.35 official. I have a pandora battery and magic memory stick i made back in the day using the (GUIDE) Make the Perfect Pandora's Battery (OLD) thread by Moose (I can't link...).
So i pop in the memory stick and the battery and all I get is a black screen with the green power indicator lit up. I know it worked back then because i tested it out, but now it's unresponsive. I tried remaking my MMS using Rain's UltraLite MMS Maker for 5.00 M33-4 v1.2
and Rain's Simple MMS Maker v1.0, but it still didn't work.
I have a Phat PSP 1001 with the magic memory stick being a stock 32MB Sony MagicGate. My operating system is Windows XP Pro SP2.
EDIT: I got it to work, I used my 1GB Lexar memory stick (I could've swore the 32MB worked back then).