PlayStation 3 TeamSGK have released a SEN Enabler/Disabler which spoofs firmware 4.25. You will need to follow the steps below which depends on which firmware you are using. Also not that before using this you will need to uninstal any other spoofs.
Roughly translated by Google:
CFW Cobra 1: Uninstall the spoof via Multiman 2: return to xmb 3: Start-SGK-ENABLE DISABLE PSN.pkg. This will ask you to select: say yes to the two questions. 4: To disable start a new SGK-ENABLE DISABLE SPOOF Unable 4.25.pkg a spoof called and it displays to disable spoof, say yes.
TrueBlue CFW 1: Downgrade your dongle in 2.5 2: return to xmb 3: Start-SGK-ENABLE DISABLE PSN.pkg. It asks you to say yes to activate 2 question. 4: To disable start a new SGK-ENABLE DISABLE SPOOF 4.25.pkg Unable to spoof itself and it will not disable viewing spoof, say yes 5:-Enjoy PSN
ALL CFW 3.55 Standard 1: Uninstall any spoof install on your PS3 (Rebug spoof style 2.2 4.11) 2: Return to xmb 3: Start-SGK-ENABLE DISABLE SPOOF 4.25.pkg. It asks you to say yes to activate 2 question. 4: To disable: run again SGK-ENABLE DISABLE SPOOF 4.25.pkg a spoof Unable say no and it shows you disable spoof, say yes
Here is a Q&A from consolecrunch linked below.
Q:*Is this tool safe?
A:*Yes. it is, this have a restore process if something goes wrong for prevent RSOD
Q:*It works with all CFW?
A:*Nop, only with CFW 3.55 and 3.56 (PKG precompiled and fixed)
Q:*It works on OFW?
A:*Nop, only for CFW
Q:*I have RSOD/Black Screen, how can i solve it?
A:*Reinstall your CFW in Recovery Mode
Q:*Fix is already complete but I have an error while log in SEN
A:*Go to Recovery Mode and choose*Restore Default Settings, Rebuild Database*andRestore File System. In some cases you need to change your login password
Q:*It works with DRM dongles?
A:*Yes, but you need to have dongle update 2.51 and not 2.70
Q:*I have CFW Rebug but when PS3 starts shows Black Screen
A:*Make sure you don´t have any spoof and Rebug Mode in Normal before installing, to fix Reinstall CFW from Recovery Menu