I'm sorry but I don't know if I can help any more. You seem to be basically in a guessing/speculating sort of mindset where any ideas I, or others, make are dismissed without any proof.
They aren't related. With the ASCII program, a few random LEDs light up due to noise.
Your proof that noise is the reason?
I guess becuase that 10k resistor isn't there holding the latch pin down..
So just guessing here.
... but that's irrelevant.
In your opinion.
... a scenario where random LEDs light up and stay on, unprompted. Not always the same ones. Due to noise.
You are just asserting "due to noise" when it could be due to low voltage. Where is the proof it is due to noise?
With the main program, the whole thing is unresponsive to commands (only when wired correctly).
There is a subtle implication here that being "wired correctly" is the cause of your problems. Not so subtle here:
For the thousandth time, it does work, but not with the recommended wiring.
I would have put back the "chaser" sketch (somewhere in the last 7 pages) and just leave that running and observe and probe until I worked out what was happening.
I suggested you make a video. Not done.
I suggested you try each chip individually. No response.
For the thousandth time, it does work ...
Right, so it works. We can close the thread.