My problem is little different. Yesterday it was no display on my computer but after removing the battery to fix this problem. I just found another problem that is, after sometimes of loading the operating system my screen disappear with different colors lines and dots. I tried it on Windows 7 and also Linux. But the problem still the same. Sometimes during the loading of home screen this problem arrives. And when lines arrives on my screen system is halted. I can't do any work. I must power off with long pressing the power button. My laptop is lenovo u41-70 i7 4gb of ram with Nvidia 940. So please anyone guide me what to do?