2 month old rig, monitor getting no signal please help!

[bjj51]

system is as follows: cpu- intel i3 2100
psu- corsair cx600
gpu- sapphire 6870
mobo- gigabyte ga-z68a-d3h-b3
cooler master 212 cpu cooler
hd- samsung spinpoint 1tb
memory- g skill 2x2gb
I've been using this setup for 2 months now without a single problem. Last night I was plugging in my speakers (usually use headphones) and it didn't seem to work (gave up on it and went to sleep). Went to plug in headphones today and was still not getting any sound out of them. I shut down the computer to restart it and as it was shutting down I noticed the cpu fan (or the case fan) got much louder than normal and it wouldn't shut off all the way so I held down the power button to get it to shut off. When I turned it back on the fan was still louder than normal and the computer wouldn't boot up (fans, hd seem to turn on but monitor is getting no signal).
Sorry for the long and convoluted description, this is my first build and I have no idea what's going on! I checked to see if any of the cords were loose or something but didn't see any problems. I have no idea what to do at this point, any help would be greatly appreciated!

 

[klabauterman]

We almost have the same problem, ive read other related posts and the generic solution was to check cable connections, check monitor cable connections, check if monitor is on the right setting (eg: vga - vga / hdmi to hdmi), check ram sticks make sure theyre plugged in, reseat vid card, try integrated graphics, if all else fails reseat everything from cpu to cables which is what im gonna do now as im having my monitor display "HDMI No Signal" good luck to us, haha