The NEW Build Your Own Arcade Controls

Main => Monitor/Video Forum => Topic started by: Mauzy on March 20, 2007, 07:07:20 pm

Title: WG 19K7201 Hold/size issues NEW INFO!!
Post by: Mauzy on March 20, 2007, 07:07:20 pm
I recently bought a beat to crap Ms Pac cabinet that has been converted many times and is currently a Ninja Clowns cab. The monitor was advertised as "completely dead" but after a little work, (plugging it in helps) I got it to come on. At first it was just a green screen with a few lines going through it, but I finally got a picture on it. This is the best stable picture I can get. This took a lot messing with the horizontal (which is in a truly rediculous place) and vertical holds, positioning, etc. I am relatively new to arcade games, and I really don't know much about monitors other than the fact that they can be extremely dangerous. I also know that it isnt a PCB problem as I have tested it in my other JAMMA cab and it ran great.
The monitor is a Wells Gardner 19k7201 made in 1997.
(http://i148.photobucket.com/albums/s39/pjmauzy/DSCF2083.jpg)
This pic doesn't do what can be seen on the monitor justice. It is surprisingly crisp.



Title: Re: WG 19K7201 Hold/size issues
Post by: grantspain on March 21, 2007, 03:26:52 am
looks like you have the wrong sinc  connected on the signal input plug
Title: Re: WG 19K7201 Hold/size issues
Post by: SirPeale on March 21, 2007, 07:20:57 am
Or the yoke is loose and has turned a bit.
Title: Re: WG 19K7201 Hold/size issues
Post by: Mauzy on March 21, 2007, 05:15:19 pm
looks like you have the wrong sinc  connected on the signal input plug

It looks like one sync wire is connected to both sync inputs, so I'm not sure what to do about that.
Or the yoke is loose and has turned a bit.

What steps would I take to check or fix that? Where is that even located? Would that involve discharging the tube?
Title: Re: WG 19K7201 Hold/size issues
Post by: SirPeale on March 21, 2007, 07:23:49 pm
Or the yoke is loose and has turned a bit.

What steps would I take to check or fix that? Where is that even located? Would that involve discharging the tube?

What if it did?

The yoke is located on the back of the tube, on the neck.  It's a bundle of copper wire loops on a plastic sheath. 

With the monitor off, grasp it and lightly try to move it.  If it moves easily, that's your problem.  If not...

If that's your issue, we'll discuss how to fix that when you find out.
Title: Re: WG 19K7201 Hold/size issues
Post by: Mauzy on March 21, 2007, 09:05:28 pm
I tried moving the yoke, and it didn't move at all... The board on the neck itself DOES move quite a bit though. That can be a problem, correct?
Title: Re: WG 19K7201 Hold/size issues NEW INFO!!
Post by: Mauzy on March 28, 2007, 10:07:49 pm
After letting it set for a while (busy with cab. stripping) I plugged it into my other JAMMA cab and was loudly reminded of the high pitched squeal coming from the component circled. Im sorry about the image quality, but it is a distinct part.
(http://i148.photobucket.com/albums/s39/pjmauzy/monitorsqueal.jpg)

When the Horizontal hold is turned up too high (very small turn of knob) it starts squealing and the picture goes green. What is this part, where can I buy it, and would it be easier to just buy a new chassis?
Title: Re: WG 19K7201 Hold/size issues NEW INFO!!
Post by: modessitt on March 29, 2007, 12:44:54 am
I had that exact same problem with the same monitor and could never get it fixed.  It is definitely a chassis problem as I put a different chassis on the same tube and it worked fine.

I did a lot of searching for similar descriptions but could never find the right info to fix the problem.  The flowchart didn't help, and after replacing tons of parts with no effect, I gave up.  The picture looked exactly like yours does.  Almost like the picture is tilted 45 degrees to the side.
Title: Re: WG 19K7201 Hold/size issues NEW INFO!!
Post by: grantspain on March 29, 2007, 03:19:22 am
this is a difficult one,i would look towards the circuit of the sinc input and whatever is decoding the the sinc input
the transformer is probably squealing as the sinc is unstable and unable to lock