Could be failed motherboard or bad screen, maybe bad RAM or some other failed part. If it's in warranty, contact support. If out of warranty test it with new RAM, try it without the hard drive attached see if it can at least get to the BIOS screen.
Could be failed motherboard or bad screen, maybe bad RAM or some other failed part. If it's in warranty, contact support. If out of warranty test it with new RAM, try it without the hard drive attached see if it can at least get to the BIOS screen.