K7000 Top Curl (partial) tough one!

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Hi;
I am working on a AS WMG PCB with a K7000 WG monitor in a Defender cab and just cannot get rid of this little curl from the top of the display.

The chassis is capped, the width coil had been replaced, I am using only Neg Horiz Sync connection, I adjusted Horiz hold to get the min curl but it just won't go away.

Right now the Horiz center is turned all the way counter clockwise and if I turn it the least amount clockwise, the curl gets much worse.

If I turn the horiz hold either way, the curl gets worse.

I tried turning the 50/60Hz and that did not help.

If I enlarge the display, vertically to get the wave off the top, I loose the score from Robotron and if I leave the curl in, if makes the radar screen in Defender and Stargate look like crap.

I don't know what is left to adjust, I think I have tried all combination's but I obviously missed something. If anyone has any ideas, other than replacing the monitor, I would be much obliged.

Thanks in advance.

Jeff
 

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I slept on this problem and did not find a solution in my dreams...

That being the case, does anyone have any real life guidance with the "curl" problem....?

Thanks
Jeff
 
ive never dealt with as boards, but if they sync anything like the imported ones, you might just have to swap monitors wirh something else.


Id try it in another cab if possible to see if its a board issue or if that particular monitor and board just dont play along..
 
I tried the board in another Jamma set with a Vision Pro and it worked perfectly.

It is the monitor and I would like to solve this problem as I have already spend 3+ hours on this $#@!.... and would like to know what the problem actually is so I will have that info for the next time, which I'm sure will be sooner than later......

Thanks
Jeff
 
Did you try a different Jamma board in this cabinet? Chances are the Arcadeshop board does not like the k7000. just like the 1000 in 1 boards don't like the k7000.
 
I was afraid of that. It's just that I spent so much time on this monitor...........
Could it be a voltage issue or should I just pull it and give up, (the monitor that is)...
 
thats what i said lol.. some k7000s are fine, some dont like it.. weired i know but true.


DO you have another game you can trade monitors with?
 
Maybe I was lucky, but I had something similar with a 4900. Turned out to be a bad pot.
 
Maybe I was lucky, but I had something similar with a 4900. Turned out to be a bad pot.

Hi;
Which pot caused your issue,was it the horiz center? - the horiz hold??
Like I said before, I did so much work to this monitor, so much time invested, I would really like to use this one and not have to start over.


Thanks
Jeff
 
Hi;
Which pot caused your issue,was it the horiz center? - the horiz hold??
Like I said before, I did so much work to this monitor, so much time invested, I would really like to use this one and not have to start over.


Thanks
Jeff

Man, I'm not sure. This was a few months ago. If it worked fine with another board then I think Ken hit it on the head. You could always replace both pots and see.

I also understand your pain with the 7000. I put a lot of time into one a while back and it's still in HV shutdown. Now, it's my "parts" chassis. I actually have 2 other 7000's that have worked great for months :)
 
This may or may not help. But I've had that problem with k7000s before. I tried on a whim connecting the sync wire to both neg horizontal AND neg vertical sync, and the problem has gone away. Give it a try....I don't think it can hurt anything.

jy
 
This may or may not help. But I've had that problem with k7000s before. I tried on a whim connecting the sync wire to both neg horizontal AND neg vertical sync, and the problem has gone away. Give it a try....I don't think it can hurt anything.

jy

I had tried that already, in fact I just tried it again, just in case and No Good!
Thanks anyway.
Jeff
 
If I enlarge the display, vertically to get the wave off the top, I loose the score from Robotron and if I leave the curl in, if makes the radar screen in Defender and Stargate look like crap.

What happens if you shrink the image a bit ? (like a 1" black border or so)
Seems you have it stretched to its max in those pics.

Also, Contrast and Brightness can affect that top curl on a K7000 sometimes.
Try turning those down a tad and watch for change in the curl.
 
I tried making the image smaller and the did not help, the problem shrank along with the image.
I will try the brightness and contrast and see if that helps, that is the one thing that I have not tried as of yet.
Thanks for the suggestion
Jeff
 
I had this exact problem on my MK1. When I swapped the chassis onto another tube, the problem went away. That was the last resort as I tried everything you have described as well. The tube was the issue for me.

Old tube with the K7000..

CIMG2646.jpg


CIMG2648-1.jpg



New tube with same K7000..


CIMG2651.jpg
 
I had th esame thing... different chassis, different game.

The solution is different for every game. In my case, I had a Kortek KTX26 in a Neo Geo. Capped the crap out of it, did some pots, and everything else I could think of, then went to the game board. I ordered a 1 slot nep geo from eBay and guess what? Same issue. Put another game PCB in this cab and the skew was gone. Put this chassis in another game and it looks great!

There is a solution, but I don't know what it is. It's different on different chassis, but there must be a solution. Try another K7000 in there if you get one and see if it follows. I have heard from someone that messing with the 50/60 pot helps it a bit.

Good luck. I wish I could solve this on my Neo Geo, but I'm holding out for a new chassis.
 
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