The display digits are most likely related to memory as you state. Faulty 5101 ram. You maybe able to clear the ram once you get the test switch to work on the coin door. You scroll through bathe tests and for the high score press the reset button on the processor board. Failing that replace the RAM
The test switch most likely not working due to connector issues. The smaller connector at the bottom of the processor is from the coin door.A1j6 Never plug or unplug these with the game on as it will stuff your board
