From your description of what is going on, particularly with the fact that plug sparks when inserted it sounds like there is a short somewhere in the circuitry and that will be very hard to find. The short be causing your electronic parts to be damaged.

These models are very good when they work but when they do not they are very difficult to diagnose. My best suggestion, which is not a particularly good one is that you replace it with a no frills no electronics top loader, and if you purchased the parts you have already replaced from this site you can return them.