If you need to reset your Sony PIN, you will have to use a Master PIN to gain access to the Parental lock settings. To do this:
 
  1. Press the HOME button
  2. Scroll down to Settings
  3. In the Personal section select Parental Lock (Broadcast)
  4. Enter the Master PIN (9999)
  5. Select Change PIN Code and change it to your desired PIN.

 

Cheers