i was having problems as my tv only had scart and everytime ...
i was having problems as my tv only had scart and everytime i rebooted the box after downloading a channell list it would automatically switch to hdmi then i couldnt see now picture, so in order to get it back to normal and give you option to let you change tv setting on boot ftp to box and try this,it worked for me
You need to edit this file /etc/enigma2/settings
change this setting to true
Reboot your receive