In this day and age, many products are manufactured as throw away products. They aren't designed to be repaired. When they fail, you throw them away and buy a complete new unit. To the manufacturers, it's simply cheaper that way. To the person who owns the assembly, it may not be if they can fix it themselves. That said I've always prided myself in being able to identify the actual component in an assembly that failed, then cheaply source/repair that part and put the assembly back in service. Knowing when to do that takes experience and it's not always worth my time or a good idea. The times that so called "experts" assured me that "You need a new one" is just laughable, but, . . . . . . that's the world we live in.
Chum lee