I got this Williams Indiana Jones pinball machine in for repair.
This machine has multiple problems.

It starts up, and it is possible to start a game.

But it ejects two balls every time.
(Bad optos maybe?)

There are no music whatsoever, and no soundeffects, just a random “ding” now and then.

When i tried to get into the test menu, it did not respond to any of the buttons inside the coin door.
So i measured all the cables from the buttons up to the connector on the CPU-board, and they were all ok.
Tested the buttons again, but still no response.

I then removed the CPU-board and placed it on my workbench to give it a good visual inspection.
Acid-damage had taken 6 IC:s and some resistors/capacitors…

So i removed IC:s and the battery holder, and will clean the board up before putting in sockets and changing some resistors and capacitors.

The driver board also has some damage on some connectors due to heating, and some hacking has been done previously that i have to fix.