One of the displays on my Eight Ball stopped working. It is a Stern display (A-434 etc) which is compatible with Bally diplays.

By switching places, I learned that the problem isn’t elsewhere. I have measured the testpoints (ok) and tested the transistors (ok). I momentarily shorted the emitter to the collector of Q19 but the ”G” segment didn’t come on.

Does this mean that all hope is gone for this display?

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I reflowed the solder joints and added a touch of new solder. Unfortunately: no change. So, I guess there is nothing more to try... or is there? Can the display itself be fixed?

It is 195 V (should be 185 V).

The voltage can be adjusted with RT 1 in the image below, right?

Dare I increase the voltage more? Can't the other displays be damaged?

Shouldn't I turn it down a bit instead?

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It was a sudden fail.

I used the Stern Service Bulletin for this display and it lead to the conclusion that the display itself needs to be replaced (no the electronics).

I will turn the voltage down in order to save the other displays.