I found this Troubleshoot on it: How to Troubleshoot a Vista Sleep Mode Problem and Find a Solution It may have an answer for you.
I had this when my previous gfx showed that it needs to be replaced. Once upgraded all problems with turning PC on for about 20 mins, were gone.
OK, so I unplugged my computer totally, then I switched the jumper so it covered the middle pin and the one opposite the original. Waited 2 minutes, then switched it back. Then I plugged in my computer and booted up, monitor still wasn't getting a read. Did I do something wrong? Was I supposed to boot my computer while the jumper was in the reset position?
k. this time i unplugged the computer, took the battery out, left it out for somewhere between 2.5 and 3 hours, then put it back in, replugged the comp, and booted. still nothing. then i tried booting with NO battery in. afaik this would mean it launches with default settings - and still no result. so the problem is not BIOS, am i right? friendly reminder - i'm using vista 32-bit. LATEST UPDATE: so. i've reset the hell out of CMOS, and my video card was WORKING after this exact same problem happened 4-6 days ago. somehow i doubt my video card is busted, because it was working after the first time this happened. both times occurred after putting my computer into "sleep" mode. guru3d brain trust... wtf is wrong with my computer?
With what you have described you have a hardware issue most likely your video card. It's not unheard of for something to be intermittant before it finally fails. If your card is still under warranty try a new one
Try setting S1 instead of S3 resume in the BIOS under power settings. Btw you're not using an Audigy card with KXDrivers are you?, because there is an issue with the KXDrivers and S3 resume....
All right, this sounds almost EXACTLY like the problem I was having, though on a different mobo and OS. What my problem boiled down to was that my PCI-E slot died on my motherboard. Thankfully I had an SLI mobo so I could just use the other slot. Since you didn't specify what type of 680i mobo you have I don't know if you have SLI or not. If you do, try the video card in the other slot. If you don't have SLI.... then it's either your video card or monitor. That's assuming it starts up and you just aren't getting input. If it's not booting up period, but has power, then it could also be your motherboard, or any other major component for that matter.
yeah, ill try putting it in a different PCI slot. question, though- my other PCI slot is blocked (not enough room for my vid card) by my soundcard in a nearby slot (which i also have a different slot for), so i was gonna switch the two. i'm not sure what kind of slot the soundcard it in but i have another near where my video card is NOW (the possibly defective slot). ANYWHO, right next to the sound card there is a small plug going into a number of pins sticking out of the mobo. i had no luck taking it out- it was stuck pretty good. needless to say, i dont want to break any pins... do i have to detatch this thing and move it along with my soundcard, or can i leave it there? i don't know if they are related. anyway, ill try all this tomorrow. i decided to leave my computer completely unplugged for 2-3 days, since last time i did that and it started up fine on the 3rd day. if tomorrow morning it doesn't boot, well... back to the drawing board.
waited 2 days and booted my comp on the morning of the third day (what i did last time). no dice. bump.