What if the Dell laptop doesn't turn on?

What model if is the LAT series or is 1420, the video card is NV according to the following method test:

1, fn+ boot built to see if the screen can be displayed if not 100% is the video card is broken direct warranty replacement block motherboard

2, boot if there is alarm sound, the back cover open the memory with an eraser to reproduce the installation test

3, unplug the battery and the adapter press and hold the power button for 10 seconds do not install the battery directly into the adapter to see if it can boot.

In short, The Dell machine can not be opened and still NV graphics card is mostly the issue of direct warranty Card