For those interested in downgrading their custom firmware v3.55 enabled PS3 to a lower firmware, there’s a tutorial for that–with video. This video will walk you through downgrading from v3.55 to v3.50, then from v3.50 to v3.40–while retaining the QA menu. Credit goes to alchybear at nextgenupdate.

You may ask yourself, “Well, what’s the point of downgrading to a lower firmware”. We don’t know, but the complete tutorial is below.

Requirements:

In order to downgrade, make sure your PS3 meets the requirements above. Let’s begin!

  1. Power on your PS3 (with custom firmware v3.55 otherOS++ and QA flagged)
  2. Go to network settings (Do not enter it)
  3. Hit or hold the following button combo: L1+L2+L3+R1+R2+down on the D-pad
  4. Follow video tutorial below:

Video tutorial

source nextgenupdate.com