Vertical banding bars, how do I get rid of them? (RESOLVED)

[Prpl_Turtle]

Hey guys,

I have to hit you guys up once again with your infinite wisdom.  I have a vertical bar issue on my monitor and it's driving me nuts.  I thought for sure a new Flyback and capkit would cure the symptoms but no luck.  My monitor is a used Wells Gardner K7000.  I'm running GroovyMame, CRTEmudrivers w/ VMMaker from my PC.  I'm using the J-PAC for sync.  Picture looks beautiful and crisp but those lines are driving me batty 

Any help would be great !!!

Thanks guys

Edit -------------------------

Ok guys I just had a thought.  Could the fact that I'm only using the h-sync's tied together to make composite be my problem?  I'm not sure if I need to tie in vertical sync with a Wells .... if I do, how do I use both vertical and horizontal syncs with a J-PAC and a Jamma harness?  Thanks again guys

Oh jeez !! Ok I realized after reviewing the schematic that I was tying -hsync to -vsync !!  Oops !!!  I removed -vsync and I still get the bars .... darn !!

EDIT (RESOLVED!!) -----------------------------

A really big shout out to Pete Mortel (the owner of Arcade Parts and Repair).  He is the guy that I purchased the cap kit and flyback from to rejuvenate my used Wells Gardner.  I shot him an email with a picture of my issue I was having and within minutes he responded and told me that I needed to replace the cap on the neck board C204 with the electrolytic that he supplied.  I had a spare cap after swap and read his note that he supplied with his kit but it didn't dawn on me to replace a ceramic cap with an electrolytic .... even though he spells it out in plain English how to replace it and that it may be needed if vertical banding occurs on the monitor after cap kit installation .... DOH !!!!!!!!!   

Pete you are the man so thank you !!!  If anybody else experiences this issue with a Wells K7000 C204 is your solution.  If a 4 microferad doesn't do the trick as per Pete's instruction upping the capacitance to 22 microferad should solve it.  I would strongly recommend adding Arcade Parts and Repair to your arsenal for buying arcade parts.  His caps are top quality and his instructions are very thorough .... but are only good if you read them   

Thanks Pete,
Adam

[mourix]

I was puzzled because it looked like a cap issue. Glad you fixed it!

[Prpl_Turtle]

I was puzzled because it looked like a cap issue. Glad you fixed it!

Yeah thanks mourix, I had no idea you could swap a ceramic with an electrolytic even though Pete's instructions spelled it out in black and white  😝 

So it does look like I'm still getting bars but they are so much lighter it isn't bugging me near as bad.  I'm currently running with the 22micro 250volt.  What can I go up to guys before anything weird starts to happen?  I was thinking of throwing in a 100micro 250volt to see if it gets rid of them completely.  Any thoughts?

[mourix]

With C204 you are adding more capacitance to the 123V line that the RGB drivers feed off. Higher values will make the line more stable, but also add load to the flyback transformer circuit.

I would not go higher than 33uF or 47 uF, and make sure to inspect the behavior closely.

[Prpl_Turtle]

With C204 you are adding more capacitance to the 123V line that the RGB drivers feed off. Higher values will make the line more stable, but also add load to the flyback transformer circuit.

I would not go higher than 33uF or 47 uF, and make sure to inspect the behavior closely.

Roger that, thanks mourix for your input, I'll update this post with results so that if it harms my chassis maybe I can prevent others from making the same mistake.  I will start with 33micro 250volt and see what happens.