Sounds like you have some deep, deep problems. If the zero out reset doesn't work, then I believe you may possibly have an expensive paperweight. You might consider contacting one of the on-line repair services for a more professional evaluation, but it doesn't sound good....
I have not personally used him, but I have never heard anything negative about a gentleman named
Chris Short. Almost 3,000 positive feedbacks and still a 100% positive feedback rating. Not too shabby!
I hope this works out for you....
SteveTaz