I have a Toshiba Satellite A105-S4334. The screen shows horizontal lines. When connected to an external monitor, the display is normal with no lines.
I tried replacing the screen and cables, but the problem remains.
Windows 7 with all current drivers.
Lines are mostly blue, red and yellow. More or less like this one:
Best Answer
In a laptop, the screen is connected using an LVDS or eDP interface, and these just transfer a series of pixel for the screen over and over again, not caring about lines.
The data is converted into lines inside the LCD screen. Hence, the problem can only happen in the screen itself.
Artifacts like bright colored horizontal or vertical lines appear when either the flex cable from the LCD screen IC gets bad connection to the LCD glass or when the glass is chipped or cracked outside the visible area. Then the IC can no longer drive specific column and row conductors to the pixels and the pixels remain either lit or dark.
If replacing the screen didn't help, I'd guess that either the new screen was defective or got damaged during the replacement.
Another possibility is that the power supply powering the LCD module, including the LCD IC is not providing stable enough power due to deteriorated capacitors. This could explain some horizontal lines, but these lines wouldn't be solid and would be changing depending on the screen content.