Monitor Issues When Veritcal Size turned up

[hclix81]

I just got a Spider-Man JAMMA cab and have been working on restoring it.  I have everything working including the monitor.  The problem is when I adjust the vertical size POT past about 75% the screen gets a horizontal line and messes up the display.  I have attached screenshots of the monitor at about 70% vertical size and another at 100%.  This is my first Arcade cabinet and the wiring looks like it was redone at some point and not very well.  The monitor is not going through an Isolation Transformer since I did not find one in the cab.  The monitor has an Orion sticker on it but I haven't been able to find any information about the monitor and am not sure where to look.  Any help would be appreciated.

[sarge]

Looks like a vertical foldover problem.  Usually caused by bad electrolytics in the vertical section of the monitor.  A mske/model of the monitor would help.

[hclix81]

Orion - A48JMX40X11  is the sticker that is on the monitor.  I looked at the Orion A1 chassis pictured on another site and it looks close to what mine is.  The POTS are labeled the same and the same ones exist.  My chassis is a little different though.  I can take a pic of it if you think it would help.