Quoted from acebathound:Exercise caution with what you do here..
I'm guessing you'd like to see if you can fake signals at the .156 header for the plasma displays, as I described in the Pinitech RETROFIT instructions.
As already mentioned, the original plasma displays were engineered with the multiplexing design of the displays in-mind. It may cause damage to attempt locking on a digit with constant current, without any multiplexing happening. Any homebrew or aftermarket display testers should probably follow a similar multiplexing rate as the machines are doing, to avoid any unintentional over-current conditions on plasma / LED displays. Even just in regard to aftermarket LED displays, there's a few using low ohm value resistors on the segments that at FULL BRIGHTNESS are then *fully* dependent on the multiplexing of the machines to be within safe operational limits of pulsed current to the LEDs. Signals faked at the bench and displays at full brightness would damage the LED segments on some of these displays within seconds... burning them out completely or damaging them to the point they only light dimly.
The LED displays I sell were all designed to not drive the LEDs so hard, which is why on my displays you can fake signals at the bench to lock on a digit continuously for testing purposes. Won't work on some other aftermarket LED displays and I'd imagine plasma displays would be in a similar boat of being damaged without multiplexing happening.
Good advise acebathound . A couple years ago I built a microcontroller-driven tester that emulates how the original boards drove data to the displays. I've used for my own purposes but kinda lost interest so it just sits on the shelf...
-Rob
-visit http://www.kahr.us to get my daughterboard that helps fix WPC pinball resets or my replacement LED display boards for model H and model S Skee Ball