Zenith B27A74R

Ok guys, I have one in the shop right now that is giving me fits, It is a Zenith B27A74R. The original complaint is that 75% of the picture is missing. I turned up the screen and have a good raster. I put a staircase generator into the aux input and I have a good signal all the way to the jungle. On the output side of the jungle (rgb drive) I see the truncated signal I only have maybe the first 2 steps of the staircase can be seen, then the signal drops sharply to the black level.  I have replaced the jungle ic, I have checked for broken smd’s and the power supply is good. I can place my finger on the board and make the picture come back. I can’t help but to think that it is some kind of surface mount problem. I haven’t checked the oscillators yet but that was my next thought.