Try taking out the hard drive and format it on your PC / Mac. After that, put it back in and try to go into Recovery Mode.
From psdevwiki.com:
- With the system in standby mode. Press and hold the power button down until the system turns on and then off again. Release the power button. It is very important to hold the power button until the console shuts off and to release the power button before continuing to step 2.
- After about 1 - 2 seconds press and hold the power button again until you hear 2 consecutive beeps. Release the power button. During this step you will actually hear three beeps. There will be one single beep then a short delay followed by the 2 consecutive beeps. Only release the power button after the 2 consecutive beeps.
- Some people have trouble hearing the beeps: the LED goes off the same moment it beeps, so the 2 consecutive beeps can also be noticed by seeing the green LED fast blink off twice.
- You will then be instructed to plug in a controller, via the USB cord, and press the PS button : "Connect the controller using a USB cable and then press the PS button".
- It may be needed (in rare cases) to reset + re-pair the controller again with the tiny button on the back (before entering recovery mode), to be able to proceed after being instructed, to plug in a controller via the USB cord.
If that works, try the sixth option to update. Use 4.91 PUP because you don't which FW it has, so it's best to install the latest for now.
Let me know how it goes