A machine's brand name does not mean all its parts are composed of the same brand. Parts and pieces may have built through other brands. These other brands should still be compatible to the actual unit though. As mentioned on the paragraph above, choose what is best according to most users. You can trust the opinion of experts and professionals with repairs.
Many chemicals both in the detergents and possibly in water can cause damages to the machine. There are some other problems like hosepipes or other fittings getting loosened in the course of time. Improper electrical connections can also cause damages to the machine. No one can predict the problems that may occur due to moisture, heat, chemicals and electricity. Overloading of clothes also can cause damage to the machine.