OT: Pentax K-mount stuck on ZX-7 body! (slr)

[f/stopblues]

I have this Pentax mount (or so I thought) "Albinar ADG" 28-85mm f/3.5-4.5 lens. A friend has a Pentax ZX-7 SLR body. He's not knowledgeable about cameras at all. He told me he was wanting a zoom lens so I suggested he try the one I had on hand. A couple days later he tells me its stuck and hands it over. The lens is indeed attached but has a few milimeters of play in its rotation. It doesn't lock in either direction and also doesn't push into the body or pull out. Also, the automated functions of this camera don't allow me to have the back open and trigger the shutter at the same time, so I can't look at the back end of the lens through the camera.

I really don't know what to do with this thing. Should I just take it in? Do you guys have any little tricks I can try? Arg!

 

[Dougg]

Chris, see if there's a small projection around the outside rim of the back, probably at the upper right. If so there would be a matching slit-recess in the body. When the back is closed, that projection could trigger a switch that signals the camera that the back is closed. Or it could be only the frame-counter reset. You might be able to trick the camera into thinking the back is closed if you find a tiny screwdriver or similar item to act in place of that projection on the back.

The lens latch simply retracts a small pin in the face of the bayonet mount that allows the lens to rotate off, so I guess that this lens is fouling some other mechanical bit of the mount.