Quoted from swampfire:

Hi all! My Paragon is finally up and flipping, but I have one problem left that has me stumped. The displays all work fine and count up in test mode, but only the first 4 digits. Digits 5 and 6 (10 and 100 thousand) never come on. I've investigated, and I know that the problem is the digit enable lines from the MPU (J1 pins 5 and 6). Specifically, with the game in digit test:
With connector J1 off the MPU, the logic probe shows J1 header pins 1-6 oscillating between low and high, as expected. It's a known-good Alltek from Skateball.
With connector J1 on the MPU and at least one display connected, pins J1-5 and J1-6 are low (though I see very occasional high pulses).
With connector J1 on the MPU and no displays connected, pins pins J1-5 and J1-6 sound different from the other digit enables (on the logic probe). Confusing, as this is the opposite of the previous symptom. But it does tend to point to a harness issue.
I've inspected the light panel's wiring harness carefully, and I don't see any shorts. No change with a different Alltek.
I'll try to borrow my friend's O-scope to get a better view of the problem.

Quoted from swampfire:

Okay, my Paragon has been 100% for about an hour now, and I just have one question left:
Why does anyone ever sell this game?? I have a bunch of other early Ballys, and I can already tell this is going to be the one I take to my grave. The layout is so diabolical and brilliant. Tap pass is critical to winning. I can't stop playing, it reminds me of Iron Man that way.