On my laptop, colored lines appear on the screen when switching the notebook. I know, that this is a problem in all models Dell XPS M1330:emotion-6:, what can I do? I live in Russia.
Attach an exernal monitor - if it shows the same fault, the GPU is bad (common not just to this model but all nVidia GPUs from this time period). If the external display is OK, it's the display panel.
In either case, this system is approaching a decade old - it's time to replace the system. It's not worth a repair.