Re: Laptop Blackout

I have an HP Elitebook 840 i7 Laptop, upon using it one day, it started rebooting itself for several times. I then switched it off with the manual switch. and now, it is powering up, but after showing BIOS HP Logo, it is turning off immediate. tried to change the power adapter but no any positive show even using the battery. I have even changed the RAM. how could i fix this?