Okay, so this is a custom-built machine that hasn't had any trouble until now. System specifications are:
Gigabyte MA790GPT-UD3H Mobo
AMD Phenom II X4 955 @ Stock; Arctic Cooling 64 cooler
4gb G. Skill
550w OCZ Fatality PSU
And when the problem occurred I was running 2x Radeon 5770 (one Sapphire, one XFX) in crossfire
Anyway, I was using the computer leisurely for gaming (SC2) as I do quite often and randomly the display shut down abruptly. I thought maybe it was just a random quirk of the machine (this hasn't happened before) but found that a hard-reset (4s on power) wasn't shutting down the machine. Anyways, after deliberating I cut power and attempted to restart.
Anyway, the machine now won't post, the display doesn't turn on, and there are no mobo beeps. What is peculiar, however, is that the GPU fan is immediately set to full speed. I have attempted to swap out the GPU for the other one, thinking that maybe it had met its maker, but it does the same thing.
Anyway, I've tried both GPU and even tried the onboard video, but nothing is giving me any display. My first impulse is that maybe my motherboard gave out, but I don't know how to test this since I don't have any extra mobo laying around. There are no beeps from the mobo, although I haven't specifically added an onboard speaker.
While I put this machine together, I'm pretty ignorant when it comes to troubleshooting things, so I appreciate any help or insight.
It may also be worth testing your memory. To test faulty RAM try using only one stick at a time and try each stick in each and every slot on the motherboard. This will rule out either bad memory or a faulty motherboard. Failing that, try removing all non-essential components and replacing each one by one to locate the faulty component. This includes everything except your motherboard, CPU and RAM.
Admittedly, at first glance it sounds like it could be the PSU but that's just educated guesswork at this point. If possible, swap out your PSU to rule out the possibility.
Let us know when you have done all of the above and we'll go from there. Good luck!
All the items are seated correctly and the RAM doesn't appear to be bad. Per the instructions I reset my bios carefully but after doing so there still is not any video output even when I have removed the video cards to rule them out as a possibility and am attempting to go through on-board mobo video.
I unfortunately don't have a spare PSU around to rule out the possibility, however, when I attempt to boot, it acts like it's booting just without any display; i.e. the fans all run (including those on the PSU), but I don't know if that's significant in the least.
If you have followed all of the above instructions and still don't have any joy then the only way forward is to start swapping components. A PSU can still be faulty even if the fan starts spinning. Do you know anyone you could borrow a PSU from just for testing purposes. Realistically it doesn't even need to be able to power your full system since you're only going to be using it for testing purposes - you just want to rule out the possibility.
Your CPU and motherboard can, again, only really be tested by substitution although the motherboard is more likely to fail than the CPU.
Your hunch seems to be pretty correct; on a whim after checking some return policies, I went out and grabbed a cheap (well, as cheap as you can get retail) 500W power supply and it appears to be booting up just fine.
Looks like I've got a PSU to get overnighted, since I've grown far too spoiled by a modular PSU and this buddy isn't quite right for me.
Thank you so much for your help, this is the very reason that I come to Tomshardware whenever a novice like me needs advice!
I may try to get my bad Fatal1ty 550w traded in, but in the meantime I decided to try out a different model and went with the Cooler Master 600W (http://www.newegg.com/Product/Product.aspx?Item=N82E168...). Part of me thought about getting another Fatal1ty, but I thought I wouldn't test fate this time.
After seeing your recommendations power-wise of 600w, glad I went with this approach rather than another 550w.
Edit: One thing that I was curious about, that maybe you have some insight into, is that the Fatal1ty is SLI-ready, but not Crossfire-ready. The crossfiring on the machine was relatively new (less than 2 weeks), but the PSU itself was about 7 months operational. I don't know much about the comparative power-supply requirements of SLI vs. Crossfire, so could it just be that my crossfiring wore on it? I originally bought the OCZ without any intention of going with 2 cards.