Dark_AleX has released an update to his universal unbricker utility for PSP Slim and regular Phat PSP units. The unbricker will now install 3.71 M33-2 directly, instead of the initial 3.71 M33 release and the no-display bug for PSP Slim units has been fixed.
Hmm... could native 1.50 kernel support for the PSP Slim be coming soon?
Download Despertar del Cementerio "Universal Unbricker" v3 / Install Guide