That really stinks to hear all the trouble that you've been having with your Plus! Man I just had to reread all the parts that you have replaced. Is this your first printer? I have a Simple metal and the only problem I have had it a defective X end stop. It was missing the metal lever. But I bought mine on Ebay as a "new" open box so I just fixed it on my dime. Other then that it's been a solid printer. It just sounds like you got a lemon and I would ask to have the entire printer replaced. You have spent enough doing QC.