Sync problem - Mr. Do!

TheShanMan

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I am working on a dedicated mr. do! project and right now I'm just trying to fire up the board with an alternate PS (ATX) hooked up to a K7000. I don't have the original Toei monitor, but it is a csync monitor. I can't say I fully understand csync/hsync/vsync and the negative variants of them that well at this point, but I think I modded my board correctly to get positive sync yet the video isn't syncing, as seen below. Looks like the board may have other minor video issues too, but I wouldn't expect that it's related.



Here is a page from the mr do kit manual describing how to mod the board for hsync/vsync.

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Here are pics of my board with the mod for positive sync. I used different pins on the connector than suggested in the manual but otherwise I think this is exactly what was called for. Wires are soldered to pins 6 and 8 and the resistors are hidden by the shrink wrap by the edge connector.

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Can someone see what I've done wrong?
 

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Doing some more research, I discovered that a K7000 will handle composite sync via whichever hsync pin is appropriate, so I connected the csync signal to the negative hsync and it syncs now.

I am still wanting to understand why the vertical didn't sync the way I had things wired up before.

And part of that is due to not knowing if a g07, which is what I ultimately plan to use with it, can handle composite sync like the k7000 can. If anyone knows the answer to this question, LMK. Otherwise I'm going to see if I can find the answer to this question via research.
 
Yes, a G07 will handle the comp sync just fine.

The comp sync trace is on pin 25 of the board, and the scat that you have provided calls for you to cut that trace if I understand it correctly.

You do not want to hook a G07 up to individual positive sync if you can avoid it anyway. It has been my experience that G07's like to run better with neg sync or neg comp sync. They will run with positive sync, they just seem to like the neg better.

I didn't understand why you were trying to do this in the first place, so I just left it alone and didn't say anything. Almost answered this for you yesterday when you posted it.
Dok
 
I think I realize the error in my thinking. Do all the mainstream monitors take comp sync? When I looked at the k7000 and g07 manuals I see the pins labeled as +h, +v, -h, -v so I mistakenly interpreted that to mean they don't take comp sync. The only way I even figured out that a g07 would take comp sync was from searching here - I didn't see anything about it in the manual.

So is it safe to assume that other monitors like k4600 and k4900 take comp sync too?

I still don't understand why the mod I did failed to v sync. There is no trace to cut. All it is saying is to not include the comp sync signal in the monitor harness.
 
I think I realize the error in my thinking. Do all the mainstream monitors take comp sync? When I looked at the k7000 and g07 manuals I see the pins labeled as +h, +v, -h, -v so I mistakenly interpreted that to mean they don't take comp sync. The only way I even figured out that a g07 would take comp sync was from searching here - I didn't see anything about it in the manual.

So is it safe to assume that other monitors like k4600 and k4900 take comp sync too?

I still don't understand why the mod I did failed to v sync. There is no trace to cut. All it is saying is to not include the comp sync signal in the monitor harness.

4600 depends on which interface card you have, but 4900 yes
 
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