Working on a 1980 Williams Black Knight pinball for a customer in Henderson. Game was just moved, and needed to be set up. Did that and found the game to generally work well (needed a few adjustments, but noting major.) BUT there was one problem, and that was with the score displays. Instead of being “solid on” or “solid off”, they had a weird scrolling effect. See the YouTube video link below for a better view of this (hard to capture in a picture.)
The problem is on the power supply. There are two 100mfd capacitors (150 volts) that “wear out” (more specifically “dry out”) over time. Replaced these two capacitors, and now the score displays acted as they should! It’s an easy fix (though the capacitors are not an easy get because they need to be rated at 150 volts or higher.) But if you have the parts with you (which of course I did!), it’s an easy and inexpensive repair.
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