K mount mounting ring

Hi All..
Im looking for ideas or inspiration. I am currently using a K5II. But after many years of perfect usage. I now cant get it to recognise most of my lenses. Pentax or third party. I suspect a misalignment of the mounting ring. As after trying to attach many lenses many times, and Just getting the F-- symbol for the aperture setting. and not being able to auto focus. I attached my 16-45 lens and now all is fine. But im now scared to take it off in case the problem reoccurs. Is there any way to test a camera mounting plate for imbalance. or will it have to be professionally exchanged ?

The two recommended approaches are :

1. Clean all the contacts (lens and mount) with an alcohol based liquid.

2. tighten up the mount screws on the camera. Please use JIS screwdriver heads, not Phillips

Thanks Peter I have tried No1 without any Joy. But will now look at option 2.