I picked up a dirt cheap TI99 last weekend with the speech box and 3 carts. It had the power supply but no video. I tried my Sega video cable since it had the same pin out but it didn't seem to work (I later researched that the pin out is in fact different) What I got on the screen with every cart and even with no cart was a screen with black and white wavy horizontal lines. I will try to take a pic later
My question is whether this may be the cable or if it is a sign of a dead unit. I'm not sure where or how to get a cable. I don't have the skill or parts to make my own and don't want to spend a lot on a gamble. Like I said I will try to get a pic later but just wondering from the experts what you think.