There aren't any special instructions. Did you install the 6 digit or 7 digit displays? Ball in Play and Match appear in the same segments (The last 2), so maybe you have MATCH turned off? Also, if you're using an Altek MPU have you set it for free play? Putting the early Bally SS machines on Free Play requires turning off the credit display.

Also, if you are using all new LED displays, you don't need the High Voltage. You should remove the small High Voltage fuse from the Solenoid Driver Board (With the machine unplugged, of course!)

Bally games also have dip switch settings that hide credits. I think all games from that era is mpu dip switch 20 to on to display credits, but double check the manual.

If the MATCH feature is set, it should show the Match number when the game ends. Switch 21 should be ON for the Match feature. However, since it is on Free play, I would assume that it would disable Match, regardless of the DIP settings. You can ask the folks at Alltek to confirm that is the case.

I looked in the Alltek manual, and it does not mention this.

As for free ball not registering, is the machine perhaps set to Novelty mode? I don't see in the manual how to set novelty mode, but at the end of the manual, it does mention play cards for novelty mode. When the Free Ball button is lit, if you manually engage the button, does it award a high humber of points (Maybe 25,000 or 50,000)? If it does then it is definitely in novelty mode.

I have 3 early 80’s Bally’s all with alltek MPU s all on freeplay but still go through the match feature at game over, should be able to set it up using dip switches.