I have a Gottlieb 6-digit display that's showing flicker on the "h" segments, but only when the display is mostly blank. If the display shows 6 zeros, the "h" segments (on these, they're the vertical segments that create the 1s) are perfect. It's only when there's a single "0" in right digit that the other digits flicker the "h". My 60V is good and steady. I've tested the 6118s (segments & digits) and they're both good. The MPU is a new Pascal. This happens on this display regardless of what player position it's in.

Flickering "h" segments (looks worse in the picture than in real life, but it's not good in real life)
IMG_2711 (resized).jpg

60 V is clean (although it's a little over 61V).
IMG_2713 (resized).jpg

Here's the signal on the "h" pin -- it's the same on all four displays even when they're showing a single zero (which shouldn't use "h" at all)
IMG_2714 (resized).jpg

Here's the part I can't figure out -- when I hook up a scope to the "h" pin of the display, the problem goes away completely. This is the same display with a scope probe hooked up.
IMG_2712 (resized).jpg

A diode test of Z1 pin 11 shows OL, but is the current somehow leaking through? My oscilloscope probe is 1MOhm, and 15pF. I'm tempted to just hook up a 1MOhm resistor and 15pF cap in parallel between Z1:pin11 and ground.
Anyone have a better idea?

The resistor packs are for the variant with the Dionics driver. I should have mentioned -- I have the Sprague driver version. But yeah, that's essentially what I'm considering doing, although I would add a 1MOhm resistor instead of a 47k.
displaylayout6 (resized).jpeg

I hunted for a bit and couldn't find any bad connections or shorts.
I'm going to settle for a 15pf cap between "h" and ground.
I hate not finding the real issue, but it looks good now.

No, I connected a 15pf cap between "h" and ground. It solved the issue and I decided to move on.