Computer start up doesnt work

[RobGogs]

ok so, i have a AMD XFX 6870 black edition graphics card, a 750 watt power supply, amd athlon x4 3.2ghz processor, two hard drives, 12gb of ddr3 memory and a ROG crosshair 3 formula MB. to cool my processor i have a CM seidon 120v single 120mm rad, and i have a problem. i tried to install a disc reader to use disc, obviously, but after installing it and turning my pc back on... well the ROG logo popped up then nothing "no signal" my computer said, ALSO before saying try a different graphics card i have and still the same. also sorta off topic i know my pc is nothing special i am only 13 so yea. after checking from webpage to webpage i have found no solution. after a while my screen wouldnt even appear, and my fans kept like restarting or lowering their rpm for a short time before speeding up again. so please help. my skype is: robgogsmc if someone wants to video call and ill show them.

[desertcomputer]

Are you able to access your BIOS 

[RobGogs]

nope i have no access to anything

[kapow36]

Sounds like a bad stick of RAM, try only one dimm and test each one. Do you get a light on your motherboard at all?

[RobGogs]

i had three but now nothing my dad thought it could have been the motherboard battery but it still did the same thing so illl give this a try

[RobGogs]

this is still before i do the ram check but i recently built my pc into a corsair 200r and it said about selecting my boot disc then i got the "no signal"

[RobGogs]

1st stick the same as before second three green lights but no screen third green lights and a slight 2 second f2 to run ios

[RobGogs]

bios

[RobGogs]

away to try 2x4gb of hyperx beast from my dads pc 1 at a time then both just incase

[RobGogs]

Still f****** nothing please help