"Wiggly" video on T40p (but not external monitor)

[noise]

Greetings,

Over the last couple of weeks my laptop has had what I would call a "wiggly" video problem. Horizontal white lines that span the length of the screen rapidly course up the screen and the image itself is sort of compressed in the top part of the screen. (But it's very obvious what stages of boot I'm at -- the initial IBM boot screen, then the blue Windows login/password prompt.) It looks kind of vaguely what I sometimes see if a monitor cable is only halfway plugged into a desktop.

For a while I was able to correct this by gently pressing on the edges of the screen, closing/opening the lid, otherwise jiggling the lid a bit. I mainly use the laptop docked to an external display, so it hasn't impacted me much.

Tonight, though, I am unable to correct the "wiggling". It seems like maybe there is a loose connector somewhere? I don't think it's the MB -- everything is fine on an external monitor.

Sorry this is a sort of inane writeup -- I'm not sure what words to use to describe the problem. I have the service manual and someone who can help take apart/fix the laptop, but we need to know the most likely cause/fix of the problem.

Poor T40p. It's been to the depot 6 times in its long happy life. Unfortunately it's passed its warranty now but I don't want to put it out to pasture if I can help it. =)

[rkawakami]

Howdy neighbor (<-- see my location)! Most likely if the problem was going away when you moved the lid around, that would seem to me to be a cable/connector issue. I don't have any direct experience with a T40p but looking through the Hardware Maintenace manual, it appears to be a little more complicated than my T23s. You will need to get to the connector shown on page 119 (step #4). If re-seating that connector does not do the trick, then you may need to get to the other end inside the lid. That basically means going all the way to page 166 where you remove the LCD panel from the lid assembly. If you have to get to this point be sure to carefully inspect the entire length of the ribbon cable for any cracks or cuts. If you find some, then replacing the cable is really the only solution; they're almost impossible to fix (some people have done it). If the cable looks good and re-seating both connections doesn't fix the video problem, then it could be the panel itself or a motherboard issue that only affects the LCD.