Sync Connectors

Fibonacci

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I have a G07 with a slight vertical roll that never quite goes away with the pot. I can get it really close, but it always starts wandering in a few seconds. I know this could be a cap issue, but everything else about the monitor is great. If I need to cap it, I will, but I figured I would try the free options first.

In going through the archives, I found a couple posts about how this problem was fixed by jumpering the H-sync and V-sync pins together on the input connector.

I will probably try that, but I was wondering if hooking the combined sync up to both pins on a monitor that did not expect it would cause a problem.

Anyone know?
 
If you're running composite sync and it's not already jumpered, then yes - you need to jumper it. This is a common repair needed if using a G07 to replace a K4900 in something like a Pac-Man. The K4900 doesn't like the negative vertical sync attached, and the G07 does.

If it's jumpered and still won't stay locked, then you need to cap it to fix it...
 
It is not jumpered now. It was in an outrun where the guy dropped the monitor as he was installing it when I bought it.

I was in a hurry, so he tested the G07 on the bench, then dropped it in for me, but left it unhooked. When I hooked it up, it had this roll problem.

I will try jumpering it and see where that gets me.

I am sure this is a bad idea for some reason, but why not just jumper it on the monitor chassis, rather than the wiring harness. Since these always want it jumped, and another monitor in that cab might not, it seems to make more sense to make the change on the board. Again, I am sure it is a bad idea, or someone would have already suggested it.

Who wants to explain it and make me look dumb again?
 
Who wants to explain it and make me look dumb again?


The sync is controlled by the PCB, not the monitor. A Pac-Man uses composite sync. Not all games do. Putting the jumper on the actual monitor would mean that operator's would have to change the monitor when swapping monitors, and operator's don't know how to do anything except take money out.

Also, remember that these monitors were specifically made for game manufacturers to put into their cabinets, without knowing how it was going to be hooked up. Taking the composite/not composite selection off the chassis made it easier for newbies to use. Just hook up the wiring already in the cab.

They didn't think that 30 years later you'd be sticking it in an Outrun.

Still, they also probably never thought about it back then. Newer monitors nowadays have a sync selection switch, or auto-sync-sensing built in.

It sometimes takes a while for someone to think up a better way. Remember when all screws were flat-head?
 
Setting the jumper on the monitor would make it compatible with all the composite sync games, but fubar it for separate sync games.

Makes sense. I knew there was a problem with that logic, just couldn't think of it. Thanks.
 
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