-
LM2596S has been a bit improperly routed, so there are a bit of noise. Possibly fixes: solder capacitors as close as possible to the unit.
-
It is better to power PAL coder via noise filter, so you need to cut one of the 5V track that power AD724 and put a ferrite bead or inductor + a ceramic and electrolytic caps to it as close as possible
-
MiniDin8 for RGB output has a mirrored layout