Samsung Dishwasher Has Stopped Operating

I purchased a Samsung dishwasher six years ago. It has never had any problems in all of these years. When it first stopped cleaning, I was advised to use Fairy detergent. We used Fairy, and the situation improved slightly, but the machine malfunctioned again after a month. Finally, the service came today and said, "Before loading dishes into the machine, rinse and pre-rinse them." I've never heard such ridiculous advice in my life. Why do I need a dishwasher after I've already done the dishes? The service representative previously stated that the machine has a problem with the main board and recommended replacing it for 2500 ₺. I regret it.