All fat and some slim models can be downgraded to 3.55 where you can install CFW. However this requires opening the console up and soldering on some semi expensive hardware that you will have to by on Ebay or Aliexpress or similar.
You may be able to mod a superslim PS3 with a Cobra ODE but I don't recommend it. There are many limitations to this method, and it is even more expensive.
Below is the complete list. Source: http://www.psxcare.com/product.php?xProd=1658&xSec=140
You may be able to mod a superslim PS3 with a Cobra ODE but I don't recommend it. There are many limitations to this method, and it is even more expensive.
Below is the complete list. Source: http://www.psxcare.com/product.php?xProd=1658&xSec=140
Quote:Phat:
CECHA - Can be downgraded!
CECHB - Can be downgraded!
CECHC - Can be downgraded!
CECHD - Can be downgraded!
CECHE - Can be downgraded!
CECHF - Can be downgraded!
CECHG - Can be downgraded!
CECHH - Can be downgraded!
CECHI - Can be downgraded!
CECHJ - Can be downgraded!
CECHK - Can be downgraded!
CECHL - Can be downgraded!
CECHM - Can be downgraded!
CECHN - Can be downgraded!
CECHO - Can be downgraded!
CECHP - Can be downgraded!
CECHQ - Can be downgraded!
Slim:
CECH-20xxx - Can be downgraded!
CECH-21xxx - Can be downgraded!
CECH-250xx - Downgradeable if it came with a 120 / 250GB hard drive. Otherwise, if it is purchased before the fall of 2011. If it had firmware 3.61 when it was purchased, you can not downgrade. Otherwise we have to open it and look.
CECH-251xx - Can be downgraded!
CECH-30xxx - Can not be downgraded
Asus N55SF, i7-2670QM (~2,8 ghz under typical load), GeForce GT 555M (only OpenGL)