I press alt + f4 and then enter to shut down my hp laptop, then after sometime when i reopen my laptop the screen show black b

[gitalidas7086710201]

I press alt + f4 and then enter to shut down my hp laptop, then after sometime when i reopen my laptop the screen show black but poweroff light and caps lock light is on.

 

[webworkings]

Those keys together don't normally shut off a computer. They are only meant to down whatever program you are in. So unless you used a program to reprogram those keys, you are not turning off the computer when you do that.

I would suggest actually turning it off. No power at all, and then restart it. See if this resolves the no display problem If it doesn't, then try the following...

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.