My Lenovo G580 laptop's display is not working. Whenever i press the powerbutton only 1power led light come's and it is stable. I also checked my fan it is working well. I don't have battery. I directly connected power adapter, bt here sometimes power cut Was happened. Again i power on my laptop and hear 4 beep code. After that same only power led and fan was working other nothing happened .
1. Turn the laptop off (not sleep or hibernate but off).
2. Connect an external monitor to the laptop.
3. Turn on the external monitor.
4. Turn on the laptop.
NOTE: You may have to press an "external monitor" button. Could be the f4 button or a button with two monitors on it, for the external monitor to work.
If you can see fine on the external monitor, then your attached display, or the ribbon cable that connects it, are your problem.
If you can't see on the external monitor at all, or the problem occurs on the external monitor as well, then it is probably the graphics card/GPU that is the problem, which may require the motherboard be replaced.