Fortune II keno pen problem on 8051 tester

[badbaud]

Converting a FII poker to keno on our 8051 tester to test our keno pens and amp boards.

Using external pen input - internal was removed long before I started working at the shop.

The pen amp puts out a good signal at pin 12 of the LM319.
The micro switch inside the pen makes a LED flash on the MPU board when the tip is pressed.

U1 still has no output on pin 6 to pin 3 of the video chip.

Removed the interface board inside the tester and replaced all 9 IC's and one transistor. Still can't mark anything on the keno screen.

Is there a DIP switch setting of some kind on the backplane board that allows the MPU to accept pen inputs?

Is some jumper or mod on the MPU board needed to make it a keno board?

Help please, the tester manual hardly mentions keno options.

[badbaud]

I took the output from the small amp board and raised the two pins on the 6N139 chip on the main board and ran the amp output directly to those pins and the pen works.