I recently purchased a 1978 Olympia SM9 portable typewriter, and though by 1978 the quality of Olympia typewriters had started to decline, in the opinion of some, I still expected a solid, reliable, German typewriter. When I started typing on this typer, everything seemed to work fine, but occasionally the carriage would jam towards the end of a line, before the right margin stop. The type would still hit the page, but all in the same spot, as the carriage would not move. Hitting the margin release and wiggling the carriage would free it, but there was no guarantee as to whether I could reach the end of the next line without jamming again.
This was a bit worrying, as jamming carriages can be a symptom of serious mechanical problems in a typewriter. Still, this typer appeared to be in great shape, and appeared to have been professionally serviced sometime. I ran a few more test lines to see if I could identify the problem; I noticed that the jamming seemed to occur right after the bell was struck, and sure enough, on the next jam, I could see that the striker was getting caught on a carriage screwhead. Somehow, the striker was leaning too far backwards and occasionally it would catch on this screwhead on the carriage and cause it to jam. Gently bending the striker forward so it stood straight up-and-down fixed the problem and all was well. Well, now I just need to clean the type and fix the return spring on the margin release.