Fix the DRNFFFFFxx error with KeyCleaner
DANGER
You must be on Custom Firmware 5.XX M33-6 or 5.50 GEN (or above) to fix this issue. Do not run this on Custom Firmware 2.XX and 3.XX or Firmware 1.50. Follow this guide to install Custom Firmware 5.00 M33-6.
The DRNFFFFFxx error means that the IDStorage of your console has been corrupted or patched. This guide will help you fix this issue and allow you to update to update to the 6.61 Official Firmware.
Get started
Download and install the Old Custom Firmware Update Pack
Download the pack here:
For old Custom Firmware: Google Drive
For 1.50 Official Firmware: Google Drive
Place the pspIdent and KeyCleaner folders in the GAME folder of the memory stick.
X:/PSP/GAME/
Identify your PSP motherboard with pspIdent
You need to know your PSP motherboard version to follow this guide. It is mandatory to follow the next step.
Run pspIdent and identify your motherboard
In the blue section near the bottom, you'll see the model (PSP-x00x) followed by the motherboard (TA-0xx). Take note of the TA part, this is what you need to know for the next step.
Fix the DRNFFFFFxx error with KeyCleaner
This error code appears if your IDStorage is corrupted or patched and prevents you from applying the update. In order to proceed with the update, you'll need to fix your IDStorage.
Run Key Cleaner on your PSP.
WARNING
It will attempt to determine your motherboard and region based on the current IDStorage, but there's a small chance your IDStorage is corrupted enough for these to be wrong, so use the info you got from pspIdent the previous step.
Press X to analyze keys
Press the key corresponding to your motherboard group. (For exemple, press X if you have a TA-082 motherboard).
Key Cleaner will scan your IDStorage keys and determine if any need to be fixed.
If you're prompted to fix any keys, do so.
Once it's done checking, you should be asked about key 0x0005, you want this key to be unpatched. Since you are running Custom Firmware 5.00 m33 which has a custom IPL, it is safe to do.
You should end up back on the main screen of Key Cleaner. Exit with the O button.
Update to Official 6.61 Official Firmware
Follow this guide to install the 6.61 Official Firmware (and then the Ark-4 Custom Firmware).