HP Probook 4720 Display problem (Black Screen at start up)

[Crossbreed]

Hello forum.

I have an HP Probook 4720 and 2 weeks ago I started having problems with it, more exactly blue screens and a few freezes (2/3), I though it was from my OS after that, one morning I power up the notebook and I have no image on my display. Previously to that I had no flickers, no weird lines on the display nor anything like that.

I connected an external display and it works, so it's not from the ram mem, the hdd has 3 days power up time. I reinstalled the OS, notebook's display still doesn't work, after reinstalling the video drivers and restarting windows won't boot up, only way is to select ''last known good configuration'' which removes the video drivers. Then I thought to check the GPU temp which is at 85/95 celsius, kinda hot.

What do you think is the problem? Can the video card be broken? If so why does the external display work? What can I try now? The screen is completely black, I mean it doesn't power up and displays a black image.

Thank you.

 

[Prostar Computer]

Does the external display work with the video driver installed?

 

[Crossbreed]

after I install the video driver, the windows won't boot up (It doesn't event go to logo screen) and it's not an hdd problem, I checked the HDD like I said it has no bad sectors and has only 3 days of power up time.

After I select Repair or Last known good configuration, it will automatically delete the video drivers and enter desktop. While the drivers are installed I can enter Safe mode though.

I really don't know how this laptop works. Does the i3 have an integrated video card and because of that the vga port works? In gpu-z the video card is detected.

I don't think the display would broke out of the blue.

 

[Prostar Computer]

This laptop has ATI Mobility graphics installed. The processor touts its own integrated graphics if I'm not mistaken, but the laptop is designed to run internal and external displays through the ATI dedicated graphics. The problem you're facing is classic behavior of a bad video chip.