I just bought a Williams Stargate and have one issue

[johnlittle843]

Problem:  The monitor has a good display and game play is fine for most novice players.  But I detect a problems in the radar screen.  By observing the radar screen and what you are expecting your location to be when you make it to the area you are in pursuit of you end up always higher than you expect you are.  This is really bothering me.   All test seem to pass, but I do notice about 4 horizontal lines at the very top 1/2" of the display.  I'm not sure if this is affecting this game play but I think it might have something to do with it. There was paperwork that appears to be recent of a capacitor kit #202 from zane electronics.  If anyone has any recommendations to help me please do!  Thanks, John