checkerboard

Hello TD! This is my first time working on a Macintosh, but I've done a lot of Arcade game repair. Ok, So my partner found a Macintosh Classic at an estate sale, and grabbed it. When turning it on for first time, nothing happened. So I took the cover off and looked closely art the boards...

Hello, My Macintosh shows a chess board despite recap and a new EPROM. I also cleaned the board. But when I take out the RAM expansion, the Mac shows valuable lines. Can anyone help me further?