SamyGO

Ok, and last question: How it possible to make accidental activation, if i wouldnt like to delete 2009_step1 firmwate on hidden partition?

Yes, I see active firmware. It is 2008, but i haven't got alternative firmware(2009).
Is it possible?

Thank you for the author. This method works perfectly for me on LE37B550A5WXXH (T-CHL5DEUC-2009.0) But i dont understand final(4?) step. I finished step3 and get 2008, works very well. You said: ""After reboot you get active firmware -2008 and 2009 as alternative."" Where can i f...