First off all, I would like to thank the original poster @wololo.net/talk/for posting this information. I thought it would be useful to have a noob friendly tutorial in our forums as well.

Deleted/Replaced some file in flash0 and cannot boot your PSP.. Sounds like you..Follow this tutorial to recover your PSP.

Requirement

  • A semibricked PSP which previously had 6.20 PRO X with access to Recovery Menu (If u installed the permanent patch, you will be able to access the recovery menu by holding R trigger while booting your PSP)
  • Semibrick Recovery - http://www.mediafire.com/?p1bv3314np30le6
  • Higher OFW (6.35, 6.39 or 6.60). I use 6.60 in this tutorial :

- 6.60 OFW for PSP 1000,2000 and 3000
- 6.60 OFW for PSP Go

Steps

1. Download Semibrick Recovery tool from here - http://www.mediafire.com/?p1bv3314np30le6

2. Extract the file. Copy the recovery folder (which is inside PSP/GAME) and paste it to PSP/GAME/ on your memory stick



3. Next download OFW 6.60 from here :
- 6.60 OFW for PSP 1000,2000 and 3000
- 6.60 OFW for PSP Go

4. Extract the file. You will now see an EBOOT.PBP file. Rename it to OFW.PBP.

5. Copy OFW.PBP to PSP/GAME/UPDATE/ on you memory stick



6. Shutdown your PSP and hold R trigger while restarting it.This will take you to the recovery menu:



7. Next scroll down to Run /PSP/GAME/RECOVERY/EBOOT.PBP and press X



8. It will now show you this message:



9. Press X to continue

10. You will now have the PSP Update 6.60 screen

11. Follow the onscreen instructions to install 6.60.

Credits to the_prototype@wololo.net/talk/