I couldn't get any video output on my Atari 800, using the RF out. after some diagnosing, and with the help of the service manual, it turned out to be a faulty Motorola 14050b, Hex Buffer. Luckily I have two of these machines and could swap the chip out to test. this machine still has no sound, so I need to fix that next. I'm not a professional KZread-er so this is a bit short. hopefully, if anyone has the same issue, this may be of help.
I would like to add at this point that my mate James did the tongue-in-cheek thumbnail :)