Wow, just thought i would share this.
I just installed Coldbirds Mp3 module for 2.71SE-B''
(The XMB version.)
And after the flashing, it would autoboot my password protect, but then the known black screen showed, and my psp turned off.
I dunno if it was a semi-brick or corrupt data, but lucky i fixed it without having to use recovery mode.
I changed the autoboot to the installer for the module, and removed it.
After that, my psp would start like nothing happened.
Phew, i got a shock...