Verified answer

you have to rule out all possibilties - which means swapping parts.

1.) Is your monitor working ?

Yes, check RAM; No , get another monitor and go back to step 1 & start over.

2.) Check RAM - pull all sticks, what happens ? pull 1 stick, boot - what happens ? pull the other and reboot ? any difference.

3.) Is it a video card or integrated video chip (motherboard video) ?

If its integrated, grab a cheap PCI video card ($20) and see if it will boot with an image now.

If its a video card, pull it out and boot the the motherboard's onboard integrated video controller

Might be the PSU - enough power to spin a fan, even light something up on the mobo - but can not power up system

4.) Checked cables ? all secure ?

5.) What happened leading up to this ?

Installed software ?, dog ate the computer ?, you were "cleaning the inside" ?, it got wet ?

This is the only way when you have nothing on screen - process of elimination.

It may be that your monitor is not working. try a different monitor first.

listen for a beep. it can tell you the problem. no beep indicates the motherboard is dead

orange light?