You've probably already figured this out but:
Door Lock Motor and Switch Assembly
If the washer lid or door won't lock the lock and switch assembly might be defective. This is a very common problem. The lock and switch assembly can fail either mechanically or electrically. Test any electrical switches with an Ohm meter for continuity. The switches should have continuity according to their design.
If the door won't latch, the door lock assembly might be defective. These are normally made of plastic and cannot be repaired. If the door won't latch and the door lock is broken, replace it.