Thanks to @Nicolas19 for this.
WARNING: USE IT AT YOUR OWN RISK. IF SOMETHING HAPPENS NEITHER NICOLAS19 OR HAX IS HELD RESPONSABLE.
After CFW 4.21 Rogero released by tick here a new CFW ARCH CEX 4.21 Beta. To install this CFW you need to be on firmware 3.55.
Beta version features:
– Bluedisk Core_OS patched CFW to 4.25 OFW aim_spu_module.self
– Consistent backup games 4. + Or original games
– SEN original connection
– Spoof 04:25
– Compatible ****PSN
– Ca.cer version 4.25 (except CA27.cer)
Do not install if the console has received a downgrade earlier
Do not install console-DEX
Install OFW from 3:55
Download and install the official firmware 3:55-
Prepare a USB stick formatted in FAT32 and create a folder called PS3, then in that same folder, create another one called “UPDATE” in which to copy the file (PUPs should be renamed PS3UPDAT.PUP).
Connect the USB to the console and turn it on.
Install 3.55 OFW through the XMB
Once the firmware is istallatoo, download and unzip CFW 4.21 ARCH-> LINK
Replace the PS3 folder on your USB stick into one file provided by the CFW ARCH4.21
Connect the USB stick to the USB port furthest to the right of your console and start the console in recovery mode
Select option 6 (System Update), and follow the instructions that appear on the screen.
Once finished, enjoy the CFW 4.21.