1. I would try going into recovery mode,
How to enter recovery mode?
a. Turn off Playstation®3.
b. Hold The power button down; The system will turn on and turn off once again.
c. Once the System has been shutdown, re-press you finger until you hear 2 consecutive beeps
d. When you hear the 2 beeps take finger off power button.
e. You will be promted to plug in your controller via usb and then hit the PS button
f. The Recovery menu will pop up.)
2.Download You firmware (Eg. Rebug/ Darknet/ Rogero ect.) Then make a folder on your desktop called "PS3" then inside that folder make one called "UPDATE" the rename the update you downloaded to "PS3UDAT", Plug that int ps3 after entering Recovery mode
3.installing a new firmware
(After Getting to recovery mode - Click "System Update" > "Update via storage media" Then agree to t and c (if necessary)
If that doest work try -
You must login or register to view this content. (haven't viewed the video, but people in the comment aid it worked (most of them)
Hope this helps