13" G07 constantly scrolls vertically, but not on test bench

ebinsugewa

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Having an issue with a 13" G07 FBO and a JROK multi Williams PCB.

On my test bench using the same exact PCB and monitor it's rock solid. However, connected to the harness in my cabinet it will not stop vertically scrolling as in the video. No amount of vertical hold or vertical linearity adjustments will get it to stop.

What am I missing? Thanks.
 
Have you tested continuity on the sync wire in your cabinet? Are there any other wires present, like a jumper on the 3-pin wiring connector? Are your testing bench and game cabinet outputting the same negative sync (or horizontal or composite sync)?

As good measure, I'm assuming you have tested all of the pots on the chassis, including solder joints? I agree, it shouldn't be those, but check the basics first.

While you're there, don't forget to check R317 and R314, if I recall correctly. Both should be 390 ohms. I've run across multiple G07'-FBO with an incorrect resistor and that affects sync.

Scott C.
 
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if you're using a pattern generator like TPG where it's wired for H+V sync, it will not roll. but if you're running the JROK with a JAMMA video plug where sync is only connected to pin 10 negative horizontal sync and that composite sync isn't connected to the pin 9 negative vertical sync, it will roll. I don't know why the G07 was designed this way. you will thus need to repin your plug to where composite sync reaches both sync pins or you can fudge it together by sticking a piece of stripped wire in both holes of the plug or I never really considered this before, could you solder bridge the sync pins together on the G07 itself?

you'll see the bridged syncs on Pac-Man and Galaga, I'm certain I took a picture, but that's many thousands of pictures I'll have to dig through to find lol
 
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