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.