Question Where do I start with diagnosing my problem? System wont wake from sleep randomly, most likely hardware issue, works fine otherwise


Dec 29, 2015
Processor: Intel(R) Core(TM) i7-8700K CPU @ 3.70GHz
Video Card: NVIDIA GeForce RTX 2080
Motherboard: ASUS Prime Z-390 Motherboard
EVGA SuperNOVA 850 G2 80+ GOLD, 850W ECO PSU

So recently I upgraded my PC, changed out the video card, motherboard, and cpu, (and monitor, maybe not important). Ever since the swap, I've been having huge issues with my new system. My motherboard has 4 lights on it, that indicate a proper post sequence, a red cpu light, orange dram light, green gpu light, and a white light indicating a good post. Typically, whenever I boot the PC normally, the lights light up in their order, and everything is fine (at least I think, I rarely have the computer shut down, most of the time asleep, this will be important later because this issue is very inconsistent). The issue has actually come from when my computer sleeps. When I put my computer to sleep, and leave for a few hours (I haven't tested to see if this happens immediately after sleep), when I come back and try to wake the computer by pushing the power button (I've had this case for years, so I'm not sure if its related to the case), the power LED lights up like normal, and everything inside the computer lights up (GPU LED's, liquid cooler LED, etc., fans even turn on). However, my keyboard, mouse, headphone LED's do not light up or respond to button presses, and my monitors both remain off (not technically off, but not receiving an input, so basically asleep). When I look in the case, I see that the red CPU light (I mentioned earlier) is activated, instead of the white light indicating a good post. So my computer is in this weird half sleep half awake state, where the fans are on and everything is on, but the computer is not sending any input to the monitor and not receiving any input from peripherals. The thing that is extra annoying about this is how inconsistent it is. If i come back from classes, there is something like a 50 percent chance it wakes normally, and a 50 percent chance it does this thing.

When it does enter this state, things get super annoying. If I hold the computer power button to shut it off, the computer shuts off, and when I turn it back on, I see the boot screen (ASUS), and then I'm taken to an American Megatrends splash screen saying system specs, and saying that the computer was unexpectedly shut off, and that I need to press F11 to run setup. I do this, enter BIOS, save and exit, and then I get the red CPU light and the weird half sleep half wake state again.

The alternative option (which is the reason I'm still able to even use this computer) is to press the PSU power switch off, remove the cable, put it back in, and press the switch back on. When I do this, most of the time the computer posts completely normally, and when I sign in, everything that I had open before the half-sleep-half-wake state is still open, so I'm guessing the computer was still able to hibernate through everything? There is no indication of a crash or BSOD, and everything is as if the computer went to sleep and woke up normally. (sometimes this method doesn't work the first time, but does on the second run).

I have no idea how to approach this problem. I don't know if it's a blown capacitor, CPU not getting enough voltage, or something wrong with the motherboard, CPU, power supply, or whatever.

2 details that might help.
  1. After upgrading my PC, i got multiple BSOD's a week, I assume because of a hardware upgrade without changing windows. I then reinstalled windows and the BSOD's went away, but this issue remained (I hoped reinstalling would fix this issue).
  2. There is a super small chance that this issue came about just a few weeks before my actual upgrade, in which case, I would be super confused. The reason I'm super uncertain if this is the case is because I feel like I have memories of this happening in the week or two right before the upgrade, but I can't remember if that was actually the case. I upgraded my monitor just a few weeks before, and I remember an issue slightly similar to this occurring around that period, but I can't tell if it was the same issue or even happened in the time I had my old build because there was no red CPU light or indication of something exactly happening because of a different motherboard, so it's hard for me to tell exactly.
If 2 is actually true, it gives me the suspicion that something is wrong with the power supply, but I'm not too sure.

Also, I notice this issue happens later in the day when it is slightly more hot and humid, but I'm probably just drawing a connection that doesn't actually exist. I really doubt that has anything to do with it, just extra info.

I just don't know where to start to properly diagnose this and figure out it out.

EDIT: I should also add that because the CPU is brand new, and works perfectly fine when this issues is NOT occurring, it leads me to believe there is nothing wrong with the CPU or CPU pins on the motherboard. I'm no electrical engineer, so take my opinion with a grain of salt. It's also the fact that resetting the PSU allows me to boot.