Checking the counters I found a faulty 74191 in D9. Replacing it I can see something better:
but the vectors seem to be “sampled” vertically. After a fast look I found pin 19 and 20 shorted of 74374 in B10 position.
This is the situation now:
There are 2 problems:
- 25% of the screen is not used
- all labels are corrupted
the next picture shows better the problems