Hard lesson learn't - make sure you use a CFW (custom firmware to upgrade with). I didn't and ended up with OFW 5.03.

Anyway use MMSX unbricker rar file - you'll find it. I'ts the way to go to get back to custom firmware and you don't have to go back to 1.50 OFW to do it. It will have 4.71 M33-2.

Use Fake card to format MS properly and then use PSP Grader version 6 to generate magic stick.

You'll still need a pandora battery.

I don't want to provide links but you'll find them - there's a good MMSX guide to use. Definitely the easiest and most reliable root.