One of my psp's became bricked the other day, so I downloaded the UPMS Sapphire V4 installer to use to unbrick it.
I have a second psp running 4.01m33 and in the install instructions for UPMS, it says that for firmware 3.80m33 or higher, the fatms371.prx needs to be installed before the IPL can be written.
I don't know much about this stuff so I installed it. Now it appears to have also semi bricked my other psp. I can still access the recovery menu but when I copied the recovery folder to revert to 1.50, nothing happens.
Is there some way I can manually remove the fatms371.prx or maybe a different recovery folder for 4.00m33 I could try?