Black screen, no BIOS/POST

[Su8perkillr]

Hey guys, Im new here, but Ive got a huge problem and I hope you guys can help me out.

I build a pc last summer (I believe it was July, its my first own build). Ill post the specs here.

Cooler: Dark Rock Pro C1 (754, 775, 939, 940, AM2, AM2+, 1366, 1156, AM3, 11) HXLVB2
Vid card: EAH6670/DIS/1GD5 (AMD Radeon HD 6670) JCXVW8
CPU: Phenom II X6 1100T (6x 3300 MHz) HD2A77
PSU: BPS-550C (550 Watt) TN5C33
Case: Enforcer (4x 5,25" extern, 6x 3,5" intern, 2x 2,5" intern) TQXMA6
DVD-ROM drive: DRW-24B3ST (24 / 8 / 12 speed) CEBA33
Motherboard: M4A79XTD EVO (AMD 790X) GDEA06
HDD: HDS721010CLA332 (1.000 GB) AEBI15 (two of these)
RAM: 8 GB DDR3-1333 Kit (8192 MB) IDIFV3J1 (this is actually 2 benches of 4GB ea)

Well, after assembling it with a friend, it didnt work, but after looking somewhat better, I noticed I entirely forgot to plug in the ATX-12V cable (CPU power supply), and thus it was logical it shouldnt work.
Now, after fixing this little detail, the thing worked, and I was happy with it. But soon after it started crashing. A lot. As in, every boot lasted 20 minutes at max, untill a BSOD happened. It has ran in this state for a while, and back then it also featured the problems I still have. After a while I decided to open the thing up, check for loose cables and such. After I was done doing this, I hung it back into the cables, while the pc was still lying sideways. When I booted it, it worked, while I hadnt even changed a thing. I guessed this was the solution to my problems, so I placed my pc on the ground under my desk. Dont worry, I vacuum the thing regularly. Im not one of those persons that whine about a stuck pc while it is simply dust :P
Anyhow, after running REALLY stable for over 3 months, the crashing came back last sunday. I had just taken apart my brothers pc for a cleaning run, and I was supposed to format the thing as well. But after I had reassembled it, it didnt work anymore. I paused work on this one, and played a game for some time (you know, pcs tend to fix themselves over night sometimes). But then my PC crashed out of nowhere, and refused to boot.
Now, here are the symptoms.
When I press the on button, I see/hear all the fans spinning. I can hear the HDDs making noises. But. My CPU cooler doesnt start up. After noticing this, I crosswired all the fans to see if the sockets worked, and the cooler worked on another socket, and one of my other case-fans worked on the CPU cooler socket, so none of these are broken. I dont see anything happening on screen. My screen stays black, and the screens I have attached to my pc dont go on. I have tried it with one screen (HDMI and PCI), but that didnt work either. If I leave the pc running for a while, the CPU-cooler doesnt get hot. This bugs me. Could it mean my CPU is broken?

Well, this is everything. I have taken the pc apart already, down to the CPU. Theres one other little thing: my motherboard seems bended a little. Not much, but just a tiny little curve. This happens because the CPU-cooler is heavy. And its one of the reasons why I gave way to leaving my pc flat instead of right up, I feared the mobo might crack one day.

Any questions? Im willing to answer any.

[stoanee]

The first thing I would do is pull everything out of the case and set it up on a non conductive surface. By the sounds of it when your mobo was horizontal it may have been shorting out on the case. Clear your cmos and see if it will fire up. Check that your standoffs are correctly located and installed in your case.

Also, vacuuming out a computer is not a real good idea as you can cause a static build up & discharge which can kill components. When you are working on your computer make sure you are grounded to it, with this cold dry weather static is a real problem. I noticed it last week when working on a computer in my carpeted basement.

[Su8perkillr]

Hmm, Well I didnt vacuum it; I merely used a vacuum cleaner on the blow stance. But I see your point. Air friction > electrostatic build up. Much like in thunderstorms.

About my own pc, I'm going to a friend this evening to see what parts work and what ones dont. He has a similiar AMD build. Ill probably post after that, else it will be tomorrow. But Ill keep you posted.

[bignick277]

I agree that the CPU dying is a real possibility. Especially if your computer was running for a significantly long enough period without the cooling fan working. However that would also be determinant on how effective you cpu cooler is. If the cooler is good enough, it may have been able to keep your cpu cool enough even with the fan nonoperational. For the meantime, and as it's the easiest to test for considering the possibilities, I would recommend you follow stoanee's advice first as he has made a very valid point and given your description, does make sense. Also, I wouldn't use a vacuum. If you want to clean a computer for dust build up, it's best to use a can of compressed air. It's more effective and it's safer for the components.