The self timer on my OM-1 no-longer fires the shutter, it gets almost to the end of its cycle and then stops, you cant release the shutter normally either - anyone got any ideas?
I had this happen when the lens I attached had a locked up apeture preview button. This was caused by replacing the missing bayonet turn limiting screw with one from a different Olympus lens that was in fact a fraction of an inch too long.
Long and short is, try it with the lens off. If it is still there, what I just told you was of little value. If not, the lens is the source of the problem.