I have a Toshiba Satellite P35-S6292 (a wide screen laptop) and this has been happening for a few months now. I get very narrow Cyan vertical lines across the entire screen. It comes and goes constantly. I thought it heat related but it does not appear to be.
It will come and go constantly. Tipping the laptop, twisting or otherwise pulling up on the screen. especially near the hinges will make it come and go, as will tapping anywhere on the keyboard surface of the case.
It would appear there is something loose somewhere, thought it does not appear to be due to broken hinges as the screen has no problem staying up.
I am frustrated beyond belief and cannot find anything else anywhere on the net.
Your lines look like in the example 2 here? Test the laptop with an external monitor. If the lines appear only on the internal LCD, most likely you have a bad LCD screen. By the way, you can find some disassembly instructions for Toshiba laptops here.
There are no instructions for taking apart display assembly for a Satellite P35 notebook, but there are a lot of guides for other models, they all similar. I’ve added display disassembly instructions for this model.