I'm not an expert by any stretch, but I think I had something similar to this on my 28KSR. I'll throw out the suggestion that you may have a code bar hanging up (I forget which one)
I am having a strange problem with a 28KSR. The characters that are physically in the top row of the typebox only print the bottom half of the character. That is, the H, M, N, O, T, 5, 9 and # are not all there. A picture is worth 1K words:
https://photos.app.goo.gl/3ttqAgXf5nkvFqeb8
I substitute a typebox from another 28 and the problem follows the machine, not the typebox itself.
Anyone have any ideas or suggestions?
Thanks in advance!
Dennis, KB6C