Hi Alexander, I am going to give you some little invasive suggestions, (understanding that you have an antenna signal) First, connect the antenna you have if it is a roof antenna in the air connection and if it is cable in the cable connection, then from the tuning menu, do an automatic and ready search. if it doesn't work you might have a problem in the operating system, try the user menu to return to factory settings and configure everything from scratch If you still have problems, if you are a technician check the tuner, if you are not, find a way to update the software if all of the above is not working I would look at the free market how much a main is worth Successes I edit you with the main sector diagram check the feeds, eye that has tension in the agc