Shuit, any other suggestions here? I only ask because I am going to want to dive right into this thing. The unit gets power, but it only displays that screen, so could it just be the cables? Need new AV cables? I haven't worked on a Turbo Duo since about 1994, and then I had the repairs manual, so it has been a very long time. I would like to get it running though.
Well, the power supply thing is pretty important. A lot of original NEC power supplies are dead now, and often the substitutes people are using lack. A Turbo Duo, I think, uses a 10v, 1000mA power supply. If the mA rating doesn't stack up, wierd things can happen. With Duos the video output will dim whenever the CD accesses, and I can imagine getting the exact problem you describe. I once plugged a 300ma PS into a Duo R, and it wouldn't even start up. It showed some sort of static screen, possiblly the very yellow/brown screen you are describing here, I can't remember.
I bought a great PS from Radio Shack. Its kind of pricey, IMO, but its 9V 1500mA...and that's actually pretty hard to find nowdays because modern devices consume so much less power. I don't know if they have a good 10v one like that there though.