Monitors get No Signal when computer is asleep and turn off instead of going into stand by
Matthew Martinez 
Ok, so I just moved and after moving I'm having a weird issue after setting my desktop back up. I can't even think of where I might look to resolve this so figured I'd see if anyone else has an idea. Before I moved, I ran my 3 monitors with one HDMI and two DVI connections. Since moving I decided to move my computer elsewhere so I don't hear the fan noise as much (even with really high quality low noise fans it's still a persistent annoying background noise to me lol), so I got some 15 foot flat flexible HDMI cables to run to all 3 monitors.
When I'm done using my computer I always put it to sleep so that I can wake it with the keyboard or mouse without having to hit the power button. When I do that now with the new setup, instead of the monitors going into stand by mode like they used to, they show No Signal and eventually power off completely. If I wake the computer up and manually turn the monitors back on, everything is fine. So this is not a bug with the computer not waking up properly.
I'm going to test a different HDMI cable tonight in case it's something to do with these new HDMI cables (although I'm not sure what about a cable could cause this behavior), but figured I'd also post here and see if anyone else had some ideas of what might cause this behavior.
A few hardware specs that might be relevant:
Video Card: Geforce GTX 970
Monitors: 3x LG 27EA63V-P 27" IPS monitors (pretty sure this is the right model number, been a while since I bought them)
Motherboard: Asus P9X79 Deluxe
21 Answer
Ok, well I have confirmed that the problem is the HDMI cables. Don't know what it is about the new HDMI cables that causes that but as soon as I use a different HDMI cable on one of the monitors, no more problems with that monitor.
Guess I'll have to take these HDMI cables back and try something different. It's more expensive but maybe I'll get a display port hub since my graphics card has a displayport 1.2 and try that instead. Would only require me to run one long wire instead of 3 then at least.
