Only one monitor works at a time

[AKMCK84]

Hey all!

So I have a weird issue that I've never seen before. Before we start my specs are :
GTX970
Corsair CX750M
8 GB RAM
AMD FX-6350

Let's start from the beginning. I came down to my office on day to do some gaming, normal every day business as usual. I booted up my computer and to my surprise, only one monitor was working (out of 3). Went through a lot of trouble shooting steps (un/reinstalll drivers, check all cables and connection both external and internal, etc.) to no avail.

So I called up EVGA customer service and talked with them, we went through all the typical questions and then he asked me to try to turn off my main monitor to see if any of the other ones came on. Sure enough, one of the side monitors came on as soon as I unplugged the main one. This seems to work with all 3 monitors. So he tells me it is most likely a bad PSU due to it not putting out enough power to feed all 3 monitors, I've been using this setup for 2 years (the only change is the GTX970 about a year ago) with no problems so I'm a little skeptical. Corsair is not open on the weekends to call them, but I've opened a ticket.

So here I am at tomshardware. What do you guys think? Could it be the PSU? I feel like my computer would at least show the monitors in display settings as options, even if there is not enough power for them. This is definitely a weird one. Any help would be greatly appreciated!

Thanks guys!

 

[Mousemonkey]

I'm running dual 970's and four monitors on a PC that has a 620w PSU so I for one don't think it's a power supply issue.

 

[AKMCK84]

After burning the midnight oil last night it looks like I finally found the culprit. Turns out it was a registry error, I ran CCleaner like I always do once a month to clean up everything and defragged my hard drive a few days back and had totally forgot about it. I guess that was the first time I had shut down my computer since then because the problem only started after booting my computer up. I had to do a fresh install of windows to get everything back up. I guess this is why backups are important, maybe I'll start doing them now (or maybe not x_ x).