No display on dell laptop

Okay I been working on someone's laptop. It's. Dell Inspiron 1420. This one you might have seem problems with the GPU. But that a the Nvida one. This one has intel hd GPU. So heres the problem the laptop starts nothing on the screen hard drive light stays on for about 2 minutes. But screen has nothing in it. But only a few times I the screen works when you start it by pressing the Fn and holding it down when you press the power button. But it takes you to the dell testing center. So dose anyone have any recommend anything.

To figure out what is wrong there are only three things that can go wrong from easy to fix to another.

• LCD cable and connections
• inverter board
• motherboard

Also remove every single removable components like ram, hardisk, power supply cables, data cables..

If it didn't work then try this::
Removing the graphics driver in safe mode might work for you. Just remove it via Device manager.