Strange WG Monitor problem.. SOLVED!

[JoeB]

I own a WG 7000 series monitor, and I've gotten it to work perfectly with my ArcadeVGA. It's a 25" monitor. I even installed a new cap kit from Bob Roberts (and it removed all the previous problems I had).

I even tuned all the settings perfectly to my liking..

The only thing that really sticks out is a problem with the first few lines.  It's almost like there is a seperation between the 3rd and 4th line, the next 4 lines are squished together, and then all is fine.

Not sure if it's a problem with settings, some caps, or the tube..

So.. here are high res pictures of it..

[JoeB]

yet another picture..

[JoeB]

Any suggestions???

NOTE: There are no speakers installed in the cabinet at this time and everything is well grounded. (I'm not a total newbie)  

[JoeB]

HERE IS THE SOLUTION

This behaviour has really gotten under my skin, so I decided to play around with the monitor.  One of the things I noticed is that when the PC was off (no signal sent to the monitor) it did not display the artifact.

This lead me to believe that it's either a PC problem (either unlikely, since I have great faith in the ArcadeVGA) or a settings problem with the monitor.

I started playing with different user configurable settings on the monitor.. and the one that started showing a change in this behaviour is a pot labelled as 50-60Hz.

It seems that this pot changes the sensativity of the board to the refresh rate.

It has the following strange behaviour:

- The more I turn it clockwise, the less tearing is visible. Eventually it disapeared.  At the same rate, overlapping in some games (mainly Midway games) on the bottom edge started occuring.

- The more I turn it counter clockwise, the more tearing is visible, yet the overlapping of the video goes away.

The image above are from maximum counter clockwise rotation.

All that's left is to find the 'sweet point' where overlapping disappears, yet tearing doesn't show.

I think I managed to find this spot.  It's where overlapping is about to start, and tearing is occuring at only a small spot on the screen..

Anyone else have similar experience?

[APFelon]

Yep. I have the same WG series monitor, and games like MK would wrap at the bottom. I upgraded from a Matrox G400 to a ArcadeVGA thinking that would solve my problems... it didn't.  After doing about three hours of research on the Internet, I finally found a site that not only described the problem, but provided pictures of the pot (very helpful). The site is insanely hard to find, though. I don't remember what I punched in to Google to find it, and I didn't bookmark it... so I have no clue what the URL is.

As an aside, I wish someone would provide a clearinghouse site of monitor data. I have been mucky-mucking around with a WG 4600 series. After installing a cap kit, I had all sorts of odd problems with it. The right hand side of the monitor was darker than the left. If someone made a comprehensive list of symptoms/caps responsible for the symptom, my life would have been made a lot easier and I would have found the bad cap sooner. Thank God Wells Gardner have techs that don't mind supporting legacy equipment.

Ah, well. Half the "fun" of a cab project is the learning process. I have done so much research while building my two cabs that I could probably have earned a doctorate in MAME.

APf

[Ken Layton]

Common problem. The 50/60 hz trimpot, vertical size, and vertical hold trimpots all interact with each other.