Looked quite a bit on Google, but:
Trying to update to 6.60 but it gives the obvious 'No need to update because 9.90'
At 5.50 Gen-D3 currently under System Software
Have the update file for 6.60 on the PSP and ready, but ^
(PSP Update ver 2.81)
I also have 6.60 Pro-C fix files and 6.39 Pro-C2 files stored on my computer
I've seen the fix where you manipulate flash0, but my problem is that I do not have a usb cord available. Only a direct memory card reader, so the tricky part for me is to get rid of the 9.90 mess without any interaction from the actual PSP, just from the files available to manipulate via Reader.
Was hoping someone could walk through how to fix this under the circumstances, if possible.