<p>Gents, I fixed the problem and I will post here the solution so it can be of use to other people. Funny that one of the PN members addressed this issue back in 2006 and got the right solution from a gentleman by the name of Gary E. so I give full credit to Gary E. Apparently cameras made by Kyocera around that time ( mid '80) like Yashica FX-3 and Contax RTS II had the mirror applied in the frame with some glue that softens in time allowing the mirror to slide down and ultimately interfere with the lens when the lens is mounted on the camera. Since you cannot push back the mirror in place (glue is soft but not melted) I had to apply heat to the back of the mirror using a hair dryer (keep the mirror up on shutter B). In about 30 sec the glue softens to the point where you can easily push the mirror back in place. Once the mirror cools down it will stay in place and the lens can be mounted and working normal. If the glue will give up and let the mirror slide again that is another issue, I was thinking to apply little spots of fresh glue on the side of the mirror to stick it to the frame but I was afraid not to damage so I'm OK for now and see how it behaves after I use the camera for a while. I'm really happy I was able to bring this camera back to life and look forward to run some film through it. Thank you PN</p>