My Gottlieb System 3 Super Mario Brothers Mushroom World has developed a problem with the swimming mode. Cannot control the swimmer with either flipper button. Flipper buttons work okay in the jumping animation and in audits and tests, can control the functions with both flipper buttons, problem is just in the swimming mode. This used to work okay then one day just quit working. I have reseated connections. Flipper buttons work in switch test, 81 and 82 I believe. I checked the opto coupler and it is okay as I figured it would be since the flipper button works for other modes. The game plays fine except for this one problem. I am going to order a new game eprom but was wondering if anyone has seen this before or has any others ideas on what to check.

I’ve replaced the game rom and the display rom, still have the same problem. Different MPU and display controller boards, still same problem. I’m running out of ideas.

The flippers flip but the character on the screen does not move so it only takes a couple seconds to hit the monster and die. The way it is supposed to work is the left flipper moves the character up and the right flipper moves the character down so you can avoid the monster fish and get to the other side of the display and collect bonus points.

File was from a working game. The checksum on it was a little different than the one I had in the game.