Yes pepe you're probably right but no one thought it could be a FW issue ? This forum could be useful with little helps, obviously no one of us "pros" probably have the time to post a step by step instruction to repair a Fireball, and anyway I want to tell that I had posted many questions, a lot of views and no reply at all , and the questions were really simple. Maybe too stupid questions for pros? Sure, but for me were important, too. I posted the same questions on other places and had a lot of answers and tips, and so did I when other people asked me.
Each one of us have specific knowledge, i.e. I am a service engineer more specialised on hardware than on software.
Probably the use of specialised tools has made people lazy, luckily I have the time for doing R&D on HDDs (some people here know exactly what I do) and DR, I have no problems talking with everyone and I know my info. can be as valuable as the recipient is able to use it - if you don't know the HW/SW structure of some drives you can have all the tools on the market and you'll still spend days of painstaking attempts to fix a drive, with almost no tools and proper knowledge you can do the same.
And that's why I am contacting people via PM rather than on the forum, everyone is welcome and I try to answer to all messages as fast as I can - my job comes first, then a helping hand if possible is given to everyone.
A little story :
When the USSR and the US were competing for the supremacy on space exploration, there was the need for a pen that can write even with no gravity and in extreme conditions like in space or outside the atmosphere... A project was started and then, after millions of $ invested, the US engineers presented a pen that could write with no air, in the outer space and with no gravity, with no ink leakages etc. etc. - The soviets arrived at the same results using common pencils

(I heard it a lot of years ago)
Best regards.