Pentax LX sticky mirror is so easy to fix
So, lately my LX's mirror started sticking so I finally summoned up the courage to fix it. Long story short, I didn't realise how easy it was to fix this so I ended up buying another "broken" LX with the mirror stuck up.. and boy it was fixed without even opening it up.
Anyway, thought I would share my findings here to help someone out who's keen to try out one of the best 35mm cameras ever produced.
So the sticky mirror syndrome are caused by one of the following:
1. The rubber behind the mirror dissolves overtime - this causes the mirror to be sticky when going up because the small metal tab that's supposed to sit on this rubber piece goes in it instead. This also causes the focus to be off. To fix this, just remove the rubber piece entirely and cut up a piece of rubber from an old collapsible lens hood. I recommend the collapsible lens hood because it seems like the rubber lasts a long time. Also, the cross section has different thickness which is perfect to find the right thickness to achieve accurate focus.
To calibrate the focus, there are two screws that can be loosened up. Just test it against a lens at minimum focusing distance and measure the distance between the focusing plane and the film plane to see if it matches up with the lens.
2. The mirror foam disintigrates inside and causes the mirror mechanism to stick
Initial fix: spray a bit of alcohol into the aperture tab on the left side of the mirror box. This worked with the "broken" LX with one go. Make sure to NOT hit the focusing screen.
Proper fix: Remove the bottom plate. gently peel off the leatherette on the left front side of the camera (when looking at it from the front). You can reuse the existing glue later. Peeling the leatherette off will reveal a few screws. First, remove the self timer mechanism (it is very to install back so dont worry). Unscrew the metal plate. Then remove the front lens mount cover. This will reveal the internals in all its glory. Clean up the internals with alcohol. Remove any sticky residue. Then, lubricate with a fine mechanic oil.
Here's a short video I have found on YT that helped me out: https://youtu.be/KQQZkeeVxNo?si=yj4Goae8CrKcTbna
Now, I have 2 fully working LX cheaper than my 2 black MXs. 🙂
Rubbery and foamy parts are the bane of vintage. Be it cars or cameras or whatever. At least with cameras there is easy replacement. Thanks for sharing the repair information!
