Vigilante on TV constant picture roll-up problem - maybe the vsync?

orc123

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Vigilante on TV - constant picture roll-up problem - maybe the vsync? please help

Hi,

please, do you have some experience with picture rolling up (or say jumping) problem when running a PCB on a TV?
I connected my Vigilante JAMMA PCB to the older 72" PAL CRT TV trough the RGB SCART connector.
I used 220 ohm resistors on RGB lines and the colors are almost perfect (maybe even a bit too dark - the resistors are probably not at all necessary in this case).

First I tried to put 1Kohm resistor on the SYNC line.
The only problem is, that the picture is constantly rolling-up approx. 2 times a second. I can see, that the picture is perfect in other ways when I use digital picture capture/hold function on the TV.

I also tried to connect some other resistors to the SYNC line (220,330 ohm,5 and 10Kohm,etc.) and it seems not to help. I see basicly no difference in the roll-up speed when I am changing the resistors, but just in the case of high resistors sizes (10 Kohm and more) it gets even badder and later the SYNC is lost totally.
I only suggest - please, is the "rolling-up" picture on TV probably a SYNC problem or something else? Can a variable resistor (POT) to ground on the SYNC line help in this situation or maybe should I also try to remove the resistors from RGB lines - could this help?
I also got into the TV service menu, but found only setting for picture size and geometry, not something like the vsync.

Please, is this probably a bug or feature of the PCB? :)

I added pictures (frozen by TVs picture hold function), how it looks.

Is there a way to fix this in some way or have I to use another TV or monitor for this?

Thanks very much.
 

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hi, I found out, that on the other TV is it working absolutely fine (just a bit moved to the left, but OK - no roll-up at all).
So I suggest, that the PCB is absolutely all right and its just a v-sync (or vertical hold) problem.
Am I right please?
Unfortunately I found no vertical hold adjustment in the TV service menu, so I will probably need only to use the other TV. Or is there maybe some easy way (some circuit) to make it work on this TV?
Thanks a lot.
 
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