I've read some of the earlier posts on this topic but am still a little unclear as to the probable cause. We have a Ti 550 where the display sometimes goes into total horizontal chaos. If you hook an external display up, there is no problem with the display there (though the Ti's display continues to flip out). Does this rule out the inverter and logic board?
It certainly seems like a mechanical problem, since moving the display will sometimes clear it up. I've opened up the case and moved the dsiplay cable around, unplugged, cleaned the contacts with an eraser, etc. This often alleviates the problem for a while, but it inevitably returns. It doesn't necessarily seem like the cable itself, since I've popped off the hinge and wiggled the wires while the problem was manifest with no effect. Pressure on the case near the connector, however, often seems to have an effect. I suppose it could be the connector or nearby components on the logic board.
It's a bit pricey to be replacing parts... and replacing the display cable looks fairly daunting. Anybody have success resolving this problem?