Screen Dim and Shakes sometimes.

[WhereEaglesDare]

Hey guys,  just got my first cab and I was having issues with the tube being dim and read some walkthroughs and watched some videos that some of the members here helped me out with, and I got it a little bit better, at least it's playable now, anyways  I have a secondary issue now.  

The picture or raster sometimes shakes, up and down, yes it is usually when someone is walking near it or someone hits the CP kinda hard, but it looks like it's more than it should be and I did see it one time where the sides were starting to bend in at the center on both sides, like the Horizontal Outputs were cutting short but only at the middle of the screen.  I hit the side and it stopped.  Any ideas on what is causing it?  Could it be related to the screen being dim?  

BTW I sdjusted the screen as well as I can, the Brightness, Focus, RGBs, and the contrast and BLC and it is as good as it will get.  Attached is a pic of the tube.

[SirPeale]

Pictures that change with impact are almost always because of broken solder joints.

Bad capacitors can also cause all kinds of picture maladies.

[WhereEaglesDare]

Well time to get the magnifier out and a flashlight out   

With the cap kits is it usually a full overhaul of caps or it really just the caps associated with the flyback and sync circuits?

[SirPeale]

It used to be a select number of caps - those caps that at the time they created the kits that were dying.  These days, due to the age of the monitors, it's generally recommended that all electrolytic caps get replaced.

[codecrank]

The dimness on one side is probably caused by one or more bad capacitors. ( I had the same issue  http://forum.arcadecontrols.com/index.php?topic=101332.0 )

I agree with SirPeale on the impact induced shakiness, has to be something loose, bad solder point or maybe even a loose molex connection.