Museum of the Game® & International Arcade Museum® Forums

Hi everyone,

I recently was gifted a defender cocktail and during my initial troubleshooting found that I am unable to get to Test Mode. When I push the advance button I get to book keeping mode, but when pushing the auto up/manual down switch the behavior of the advance button does not change.

I bought the cocktail manual from tnt which has all the schematics.

So far I have done the following:
Checked the wiring is correct on the AU/MD switch. It is good.

Verified the switch isn't bad, tested with meter, switch is open and closed as expected.

Traced blue wire from switch to rom board pin 1 on 2J3 connector.

Verified the connector is making contact to pin 1.

Checked resistor value. Checked good.

Tested Pin 9 on IC24 (14049) on rom board with logic probe. nothing when switch is open, high when switch is closed. Pin 10 is always high.

Pin 2 on IC22 is also high. I don't see what this chip is though…and I'm not sure where the output would be. I highlighted the path of this in the schematic attached.

Any suggestion on what to check next? Or maybe I need to replace the 14049 on the rom board?

Thanks for any suggestions!