[Article 6300]Troubleshooting Asteroids pcb (2)

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:asteroids pcb oo3

There are 2 problems:

  1. 25% of the screen is not used
  2. all labels are corrupted

the next picture shows better the problems