I have a Dell i1546 it will power up but after 15 seconds it shuts back off what could be wrong

[Mrsleonard]

My laptop powers up but won't stay on the screen stays black an it turns off again after 15 seconds

 

[coovargo]

I1546 is notorious for having issues with the GPU solder failing. In fact most of the dell laptop lineup in this particular line and many others have this issue. You have explained the symptoms nearly perfectly.

For last ditch efforts, Try reseating the memory modules just to make sure and if you can dead boot it. Remove battery and unplug it, remove cmos battery if accessible. Power it on to discharge the internal capacitors and bios. Put it all back together and try to power on normally.