In 10 years of washer repair I’ve never seen a main be the issue for No fills. Most folks don’t no crap about Samsungs so everything must be a board issue. Hard to say without seeing the unit but if it’s not turning on then probably the board. Also could be sediment in fill valve screens, bad harness, open solenoids on fill valve assembly, motor issues not completing start program loop. Hope it is the board and you don’t get the runaround!