Okay, I also found the manual on several sites - but I don't want to pay for something that probably wont help me.
I've tried the "stand by - mute - 1 8 2 - power on" about 40 times, fast, slow, and holding my hand in front of the remote until pressing power on - nothing works.
I maybe have to find a TV, where I'm able to correct the picture from inside the TV. Getting to the service menu sucks on this TV.