For a while every now and then, my computer would have trouble, where the tower would turn on and the fans and such would spin up but no video would show on the monitor. I would just keep resetting the pc and messing with the components until it FINALLY showed audio. Iv'e never been able to pinpoint the problem. Now no matter what i do, the video won't come back. I've tried reseating everything, even the cmos battery. Tested the monitor and the gpu, i tried the onboard video instead of using my 660 but still no audio. iv'e done more TESTING but i can't seem to get it going. Any help would be appreciated.

Things i didn't do.
-replaced Cmos battery completely.
-tried a different PSU
-tried another motherboard.
Theres probly some other things iv'e missed so any suggestions would be great. 

-H80i corsair water cooled
-CPU 3570k
-GPU gtx 660 2gb
-1tb hdd
-90gb ssd
-mobo asus p8h77-v LE
-PSU cx750mPlease list your full specifications so we can see what sort of hardware we're dealing with.
Do you remember if anything changed or happened before this problem started, or has it been an issue ever since you've had the PC?I'm pretty sure it didn't start until about two months after i built it, which was only two years ago. and now i just can't get it to turn back on LIKE i usually can. it only happened maybe once or so per month. Usually only when i moved the tower from one place or the other, now it's just doing it.What make and model is your SSD?  Ditto for RAM?  If you've tried another board and PSU (what make/model PSU and motherboard did you try?) then I'd probably RULE those out at least tentatively.
If this is happening only when you power the PC on, rather than happening while it's already on, you have what is known as a cold boot issue.  This can be caused by a variety of things, but it's often down to the PSU, motherboard, RAM, or settings in the BIOS.The ssd is an 840evo samsung i think.
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Hang on...I may have missed an important part of your post, for some reason I thought you were troubleshooting the ongoing issue of your PC not powering on properly, but now I can see you've said it's powering on but with no video - I do apologise.  Still, the information I've asked for which you've given has been relevant so not a waste of time.

First things first, strip the system back as much as you can.  You said you've tried without the GPU, which is a good start.  Remove the GPU, all but one stick of RAM, all storage and optical drives, leaving you with just the motherboard, CPU, one stick of RAM, and obviously the cooler and PSU.  Try the system with each stick of RAM individually in the slot closest to the CPU, or the slot second from the CPU if that doesn't work.  If you still get no output, let us know, and we'll advise what to try next.
If you get the system to POST and display video, start adding things back one at a time - add sticks of RAM first, then optical drive/SSD/HDD one at a time, then the GPU.aha alright. I got this cheap sound card a couple months back so i could switch between my headset and speakers easier. It's a diamond xtreme sound 5.1. I t looks like that was the problem somehow. my computer starts up like normal now without it. Thanks so much for the help! Good to hear you managed to solve the issue.  It may be worth checking if that sound card does the same in another PC, just to check if it's an incompatibility issue with your system or that the sound card is just faulty.might just do that.