I wanted to play a newly acquired Super Mario galaxy II and at one point I was informed that I could switch to 60 Hz. I followed the instruction and went to the general menu settings of the screen and chose 60Hz from the option available.
My screen went grey even though everything else was working ie control and sound.
I can not return it back to the 50 hz because I can not see the screen.
I tried to reset with a combination of Reset and + it also did not work, i turned it off on unplugged it.. no way.. I keep on having my grey screen...
Anyone has an idea ? Is there any hard reset ?

Thanks for any help I am lost and my kid will kill me ..

PS I use the side 3 cinches -red,white, yellow.- connections on the side entrance of the TV and up to now it worked normally..