After making a bit part disassembly (lower frame), I cleaned and tested....issue continues....so I will left the camera aside, I will check with some shop making repairs around, but I think that camera value is under repair cost.
Really thank you for your help and comments. Really appreciated.
I had the same problem with my XR-P, the mirror has dropped because of weak glue. I was able to take off mirror and reposition it and mirror now works properly.
What glue did you use for the mirror? I have a Nikkormat EL that the mirror came loose on, and I used super glue. It looks OK, but there were probably better glues to use.
Super glue was probably ok, you won't have to worry about it. I didn't use any new glue there seemed to be enough sticky substance left to just move the mirror and press it back on. I might regret that later, but I will keep an eye on it.
Had this happem with same camera several yrs ago, the glue that holds the mirror in place weakens and lets the mirror slide down to where it hits the back of the lens, most notable with using a winder. Solved with super glue