Good evening , Volkmar ;
It's very simple : switch on the device with the remote control ,
select the "Settings" function in the menu and select the lowest setting
lowest setting (in my case the 23rd) " Reset to factory settings ".

Best regards from Chur ,

Sergio Minniti

however, did not help, the ulcer is still swallowing itself

Using the remote control
Press the menu button,
with arrow buttons left or right to Settings,
Enter,
scroll down to 23/23 (see footer),
Destination reached (reset to factory settings).