Originally Posted by
isoguy
You can only downgrade a PS3 to 3.55 if it came on that firmware (or lower) from the factory. The newer PS3s are being sent with newer firmware, so you can't downgrade them to a firmware they were never on.
i.e. If you want to downgrade a PS3 to 3.55, it's going to have to be an older PS3, not the new ones.
EDIT: I've also got a question of my own - i've been looking around for second-hand PS3s and I'm aiming to grab an old one that hasn't been updated (or at least can be downgraded). I will ask the seller when they bought the PS3 (this will give me a lead) but I'm hoping someone can inform me of what year I'm looking for (2010, 2011 etc). What is the year in which the newer PS3s were sent with new firmware?