DESKTOP PC Broke. I need help :_:

[Rozzok]

Alright let me begin here. MY specs ( Motherboard not included, Its Like a Gigabyte HM55 something )

Nvidia Geforce Gtx 650 2gb Gddr5

4 Gb ram ( Changed to 2 last time I booted my pc.....hmm.. )

950GB Harddrive

Intel I3 @ 550k QUAD-CORE

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So I recently installed a new graphics card and it worked perfectly fine. When I shutted off my pc to look at my ram ( It apparently was 2 what my computer said ) I turned it back on to find out it would stay on for like 5-10-15 Seconds With no display or beeps. then shut off. Is my ram faulty? My power supply is 480 and my graphics card is 400,

Maybe my power supply died? One of my friends said so.. So...... YEAH, Im on my laptop. and no I CANNOT boot my pc past the black screen, I guess its my power supply.. I really dont want to go back to my Ati raedon HD 5400 Integrated graphics.

What do you think it is? ( Ill try to post pictures later. if my cousin lets me borrow her camera...that is. )