I was hoping one of you might have an idea where I should start looking.
I am going to look at a friends Tri- Zone soon but I don't know a lot about early 80s games.
Below is a copy and paste of his problem.
If anyone has any tips on what to start with that would be great.

"The one that causes me the most grief is the oldest one (1979 Tri-Zone)
It powers up and plays just fine.
However, the bottom row of lights on the header don't work (player 1,2,3,4,
game over, tilt, high score, etc.) "

I would imagine it is just a broken or crimped wire someplace.
Was just hoping somebody had a similar problem on a game of the same era and would know what connector to start from. But I guess I can follow it backwards when I get there.
Those wire bundles are not the easiest things for following a wire.

Thanks for the offer. I will know more when I get a chance to look it over later this week.
If I need anything like that I will certainly let you know.