Sudden black screen on HP laptop

[theSplinter]

I was on the internet, (some surfing) when suddenly screen turned black. I couldn't do anything, there were no sounds. Then I restarted my laptop but it was just the same as before restarting it(black screen). But fans are running.
Specs:
-HP ProBook 4720s,
-Windows 7

Please help me to solve this problem. Thank you.

 

[nukemaster]

First thing you should do is take a flashlight and shine it close to the screen to ensure the screen is in fact black and not just a back light failure. When the back light fails the screen can appear to be back, but is in fact just no longer LIT.

If it is this, you need to replace the backlight/inverter or screen it self. This is not for users who are not used to laptop repair. If you use the laptop at home, it may be a better option to just connect it upto a normal monitor and use it as a desktop.

Now if you are indeed BLACK, you can have any number of failures(memory/cpu/board/screen it self).

You may be able to test the laptop with another screen the same way. Try the NF key combination to try to alternate displays to see if the external screen comes on or not.

It is a bit hard to pin down the problem over the internet.

 

[theSplinter]

Thank you for the reply!
I tried to shine in the screen and is black.
Then I tried to connect it to a desktop monitor by VGA and to TV by HDMI(I tried FN key combination) but there nothing appeared on the both screens. So I suggest there is nothing wrong with screen.
By the way HDD is spinning.

 

[nukemaster]

If you know how, you can try to remove and reinstall just a single stick of memory(if you have 2 or even try to boot without memory to see if the system beeps at you). sometimes memory issues can cause similar issues, but most systems will BEEP about such a problem.

 

[theSplinter]

I tried to remove a stick and no effect. Then I put it into another slot with no effect. Then I put in a stick from other laptop(tried in both slots) and still no effect. And there are no beeps. But when there is no stick in laptop, fan keeps restarting but HDD spinns all the time.

 

[nukemaster]

The laptop should be able to actually start even without the hard drive. It will not make it to windows, but with cpu + memory and not hard drive, you should at least get something on the screen.

 

[theSplinter]

I understand that, so there is probably problem with CPU or is there something else?

 

[nukemaster]

It could also be the board. with everything being on a laptop board it is hard to tell exactly what part has failed.

A repair shop that can look in better detail may be able to find out what part and see if it is user replicable.

 

[theSplinter]

OK, I'm taking it to repair shop to figure out if it can be fixed.
Thank you very much for trying to help me!

 

[nukemaster]

It sucks that notebook parts are not as easy to self test as desktop parts. hope it can get fixed up. Worst case at least pull the hard drive to get your files off.

 

[NexusLT]

Hello, theSplinter. Did the repair shop managed how to repair your computer? If yes, could you please tell me what was the problem and what part was changed?

 

[anojcool]

I was on the internet, (some surfing) when suddenly screen turned black. I couldn't do anything, there were no sounds. Then I restarted my laptop but it was just the same as before restarting it(black screen). But fans are running.
Specs:
-HP ProBook 4720s,
-Windows 7

Please help me to solve this problem. Thank you.

Hello..
I have exactly same problem as yours. I tried all the steps as u tried that u mentioned here. But not able to fix it.
Have you solved this problem if yes then tell me in which part of ur laptop had the problem.

Thanks in advance