Williams Negative Sync Modification ???

KillerKades

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This one has me scratching my head. Can't seem to make sense of this. Here are the details.

1. I am de-jammatizing a hacked up Robotron with a G07 as the monitor.

2. I have a new repro harness and the video for Williams games is positive hsync & vsync. I can't get the picture to sync on the G07 using the 6 pin header. I first thought maybe a monitor problem in the sync circuits. Everything seemed to test ok in those circuits. I examined the hacked JAMMA harness and noticed it was using pin 7 of the video connection on the Williams CPU board as csync but was connected to the 3 pin header on the G07 for negative csync. So I tried to hook it up to the negative sync 3 pin header and was able to get the picture close, but was never able to get it to lock horizontally. I would always get some sort of roll -- sometimes fast, sometimes slow. This again, pointed my in the direction of the monitor.

3. So I hooked up a WG who knows what (not sure the model) monitor to the Robotron board and tried the normal (separate h+v) positive sync and it was rolling all over the place. Moved the sync to the negative header and bang -- had a stable picture. Only issue was I could not adjust the horizontal position enough to make it center. No biggie, just testing.

4. Thought the G07 might have a sync issue. Pulled it and put it in my Joust out in the garage (with the positive 6 pin header) and had a stable picture. So maybe it just has an issue with the neg sync circuit. Who knows.

5. So this is leading me to the Williams CPU board only putting out negative sync.

Here come the questions.

Q1. I did some searching here and found that the CPU board does put out csync at pin 7 of the video connection. Which would be positive csync correct?? And to get negative csync you would cut/remove W1 to make it negative?? My W1 is not cut, but somehow only syncs to negative sync (on the WG monitor). Do I have this correct? Or how else can this be modded to put out negative sync?

Q2. To test if the CPU board is really the culprit, can I pull the Joust CPU board and drop it in the Robotron without any chip swap?

I have spent 6+ hours on this issue and maybe making some progress now, but this moving monitors and swapping wires is driving me nuts and I not sure if the G07 is ok since I can't get it to sync via the negative. So, what y'all think.
 
Theres a way to switch the sync signals from positive to negative by using a 7402 or 7404 chip. I don't have it in front of me, but I believe the circuit was in the back of an old manual like JailBreak or Bottom of the Ninth possibly. ( Can't remember right now, it may come back to me ).
 
Theres a way to switch the sync signals from positive to negative by using a 7402 or 7404 chip. I don't have it in front of me, but I believe the circuit was in the back of an old manual like JailBreak or Bottom of the Ninth possibly. ( Can't remember right now, it may come back to me ).

Not looking for a way to change it, just looking to find out why it is putting out a negative sync (it should be positive)
 
Q2) Yes, you can swap the CPU between Joust and Robotron to see if the problem is CPU related or not...
 
Q1. I did some searching here and found that the CPU board does put out csync at pin 7 of the video connection. Which would be positive csync correct?? And to get negative csync you would cut/remove W1 to make it negative?? My W1 is not cut, but somehow only syncs to negative sync (on the WG monitor). Do I have this correct? Or how else can this be modded to put out negative sync?

Put a jumper across W1 to verify that it is not open, and test for positive sync.

Also keep in mind that a G07 when using comp neg sync usually needs input to both -V & -H, where a WG only needs to have input on the -H.
 
UPDATE: The CPU board from the Joust works just fine. So the issue is CPU board related.

I was going to keep the Joust CPU in the Robotron for the time being so I started adjusting the picutre to center it horizontally and accidently connect the jumper to the vertical pin and had a laser light and fireworks show. Now I have the G07 in HV shutdown. Now that make 2 G07 chassis in HV shut down.

Tell me why I'm in this hobby again? Walking away for a while otherwise I may just go postal on the monitors and I have no patience to repair them.
 
Here is a link to probably more than you wanted to know about Williams boards and the video output: http://www.robotron-2084.co.uk/techwilliams2jamma.html#video

ken

Good information on the video part of the site. The site shows cutting a trace to invert the csync to make it negative. I found that trace to be cut on my CPU board so I bridged it with a resistor leg.

Cool I thought. Well it still doesn't work with positive sync. :( I'm still lost. Here is a picture of the board showing the cut trace and my jumper to reverse the cut. Not sure where to go from here -- anyone want this damn board before I blow it up? :D

DSC04329.jpg
 
Has this G07 been completely rebuilt? I'd check the B+ first, I'm betting that some of the power supply components might have blown when you did that.
 
Good information on the video part of the site. The site shows cutting a trace to invert the csync to make it negative. I found that trace to be cut on my CPU board so I bridged it with a resistor leg.

Cool I thought. Well it still doesn't work with positive sync. :( I'm still lost. Here is a picture of the board showing the cut trace and my jumper to reverse the cut. Not sure where to go from here -- anyone want this damn board before I blow it up? :D

Send it my way, I'll see if I can get it running for you. PM for shipping details.

ken
 
Also keep in mind that a G07 when using comp neg sync usually needs input to both -V & -H, where a WG only needs to have input on the -H.

No it doesn't... You can put in -Csync on either or both -H/-V and it'll work fine.

-Syncs are inverted by X305/306 and combined through R313/316.
+Syncs are combined directly through R313/316.

The HA11244 and the blanking circuits all work off +Csync.

Why don't you actually learn something about circuits before posting more ignorant blather?
 
Why don't you actually learn something about circuits before posting more ignorant blather?

1. Why don't you come see me in person, and we will discuss it.
2. Why don't you learn how to repair a Sanyo 20EZV before you go and screw someone's up, then run off leaving them with a busted monitor?
3. Why don't you go out and actually repair something, instead of spewing trash onto others?
 
No it doesn't... You can put in -Csync on either or both -H/-V and it'll work fine.

It may depend on the game itself; I've got an Aero Fighters PCB I've been using as a video signal generator, and I've found that I have to hook the sync to both -H and -V to get it to lock.
 
1. Why don't you come see me in person, and we will discuss it.
2. Why don't you learn how to repair a Sanyo 20EZV before you go and screw someone's up, then run off leaving them with a busted monitor?
3. Why don't you go out and actually repair something, instead of spewing trash onto others?


#1. If I came to see you, you'd be just as wrong as you are now. How does proximity change your ignorance?

#2. Why don't you stop spewing utter bullshit? Whose EZV are you claiming I fucked up, or are you going to admit you're just pulling shit out of your ass again?

#3. I repair stuff all the time... i just don't feel the need to post "Yippie, Look what I did" every time I do.
 
It may depend on the game itself; I've got an Aero Fighters PCB I've been using as a video signal generator, and I've found that I have to hook the sync to both -H and -V to get it to lock.

It likely has a weak sync output and isn't turning the NPNs on fully, so it needs to the drive from both transistors to get an effective signal through. Check the DC levels coming off the board -- could be a bad video ground too... I've seen that on quite a few JAMMA boards.
 
#1. If I came to see you, you'd be just as wrong as you are now. How does proximity change your ignorance?

#2. Why don't you stop spewing utter bullshit? Whose EZV are you claiming I fucked up, or are you going to admit you're just pulling shit out of your ass again?

#3. I repair stuff all the time... i just don't feel the need to post "Yippie, Look what I did" every time I do.

1. If you say so Cupcake.
2. Yep, never happened.:rolleyes:
3. I believe you :rolleyes:
 
1. If you say so Cupcake.
2. Yep, never happened.:rolleyes:
3. I believe you :rolleyes:

If you're going to post allegations and threats, you should at least have the balls to back up what you say with facts.

I posted FACTs and detailed information from the schematics to prove you wrong, and your only retort is unfounded allegation.

Weak.
 
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