I've tested the high quality HDretrovision cable as well as the crappy Chinese cable on 4 different TV's now with the same issue. 2 different TVs of differing vintage and make in my home and two TVs at the game store.
We also tested both my turbografx 16 console and the owner's turbografx on 2 separate TV's at the shop using both types of cables with the SD3 and produced the same result.
so that's 4 tvs, 2 different cables, and 2 different turbografx consoles with the exact same results using my SD3.
if the SD3 had the same results on two different TV's with 2 different consoles and 2 different cables then is it not safe to say that it's the SD3?