I had this same problem and was able to fix it. Here are the details:
Scenario in Sequential Order:
First - after putting my pc to sleep, pushing the power button would turn the pc on but none of the screens would turn on unless I force-shut down my pc by holding the power button down.
Second - When I could get my screens to turn on, only two of my monitors functioned properly. The third monitor would be detected but "Display Settings" wouldn't allow me to extend to the third screen. I could choose the "Extend desktop to this display" but my pc would just freeze and revert the change after about 5 to 10 seconds.
Third - I tried restarting my pc and it would no longer turn on. (Panic mode initiated).
The Problem (In my unprofessional opinion but based on past experience):
There were way too many devices plugged into one single circuit.
Explanation - My pc's power supply (PSU) was not receiving enough power to properly power my graphics card. Specifically, I had - 3 monitors, 2 additional laptops (I work from home), 2 chargers, a fan, and whatever other devices located in different rooms but still on the same circuit - plugged in at the same time.
The Solution:
I ran an extension cord from an outlet on a different circuit to my pc, and only my pc.
Explanation - This fixed all my issues (excluding daddy and marital issues). I initially tried plugging my pc into the outlet nearby, which was on the same circuit, and that did not work; the pc still would not turn on. To elaborate, and based on my limited experience working with electricity under my neighbor electrician's supervision, each circuit in a home can only handle so much load (the amount of energy each device/appliance takes up added together) and when that threshold is met, things stop working properly. Think of when you turn on a vacuum or other big appliance and the lights flicker. The flickering is your lights screaming "I'm not getting enough power for my intended purpose." This was the scenario with my monitors except my third monitor couldn't scream, it just kept quiet.
Thank you to anyone reading this and I hope this solution and the lightly sprinkled jokes could brighten your day. I know you're probably frustrated or panicking if you're coming across this forum.
Note: I also dusted my pc out as best I could, so this could have contributed to the third monitor solution but did not solve the no power issue, so I still think adequate power was the main culprit.
I've got 2 monitors working through serial
- What? How are these monitors connected? VGA? DVI?