Hardware PC turns on, but no display. No power to mouse and keyboard.

Hi everyone,

My computer turns on but there's no display to the monitor. And the monitor works I can confirm that. There's no power to the keyboard and mouse. Occasionally it turns on, but it's too random.

I replaced my motherboard but that didn't solve the problem. Please help.

Long story:

I am having a really weird problem with my PC and I just can't pin point the culprit.

Firstly, let me give you a background. I had a PC that I built about 6-7 years ago which was running fine, until one day it would turn on, but won't display anything on the monitor. My mouse and keyboard also wouldn't receive any power, even though the fans and led in the case were all powering up. I had tried everything, memtest, breadboarding, and couldn't figure out a solution. What was weird was that my PC would turn on randomly, but if I turned it off or it went back to sleep, it would go back to the same problem of not turning on (until it randomly would).

So I was done with these games. And I decided I'd build a brand new gaming rig, which happens to be my current system. Everything runned fine for the first few weeks, until I received a BSOD one day. The stop error read: "Whea_uncorrectable_error".

I thought maybe it's a one-off incident but the BSODs kept becoming frequent. Sometimes the stop error would change, but most of the time it was the same as before. I read about it and it said it meant a hardware issue, but I still thought maybe it was some conflict with any software.

I rolled back windows update and I also tried restoring my PC to a previous date when it was working fine, but to no avail. I was trying to see what activity was causing the BSOD, and for some time I was starting to think it was the external network adapter which was causing it, but even after removing it the problem persisted.

I started noticing that my computer kept making a sound it makes when you connect/disconnect something on the USB port, even though I wasn't doing anything of that sort. A couple of my USB ports actually stopped working. I was trying to figure out what was causing all this, when one day I just tried to wake up my PC from sleep and it turned on, but to my frustration, gave me the EXACT same problem as my previous/old computer. The computer would show led lights and fans running, but would not power the keyboard or mouse or show any display on the monitor.

I tried restarting a few time, unplugged the power cable from PSU and pressed the power button for 60 seconds to discharge the remaining power, and then it turned on fine. But in the next restart it again had the same problem and this time it would not restart whatsoever.

There was a power outage in my area before this problem happened (I think even the first BSOD happened after that event) and after reading online and my own deductions, I thought maybe motherboard gave up. Obviously everything is under warranty so I gave the motherboard for RMA and I got the replacement with a new piece. I installed it and the machine ran fine. I thought maybe I fixed it. And it ran without any problems for sometime. There were no BSODs. But then one day I tried to wake it up from sleep and the same problem. No display. No power to mouse and keyboard. After few tries, it turned on and booted fine. With no BSODs. However, I did notice some glitch in the display during normal usage. Makes me think: could it be the GPU? I thought maybe the sleep is causing this, so I shut down to test, but even after that the computer wouldn't turn on. After some workaround (like unplugging/plugging the power cable) it turns on, but it's too random coz sometimes it works and sometimes it doesn't.

And that is the current state of it. I have got a UPS in place since I got my motherboard replaced, just to make sure that there's no harm to my PC from sudden outage. On my UPS, it shows usage. And when my PC turns on (but doesn't boot, stays black) the usage is around 85-90v. And when it randomly turns on and boots, the usage goes above 130v at idle.

Please help me, this problem is killing me. My work relies on this PC, and despite being a PC owner for many years, I just can't figure out a solution. The reason I posted the back story of my previous build was because of the unsettling fact that it had the same problem. I even brought my new system to a different room just to make sure it's not the power outlet.

Also, the orange qled light for Dram is constantly on in my recent attempts. I tried swapping the rams, removing the rams and the GPU, but no luck. I have tried clearing the CMOS (through the button and manually reseating the battery). I also tried to disable the sleep settings from power management, but I am not sure if that is causing it because the problem remains even if I shut it down.

I have a warning speaker connected and it makes absolutely no beeping sound (unless it randomly boots into the system, then it makes a single beep sound).

Please tell me what should I do.

My config is as follows:
Ryzen 9 3900xt
Asus ROG Crosshair VIII Hero
G.Skill Trident Z Neo 3600 32gb x 2
Colorful RTX 3080
SilverStone IceGem 360
Coolermaster MWE 850w
Lian Li PC-O11 Razer Edition
ViewSonic VX2776-SMHD
Windows 10
Netgear Nighthawk AC1900

Thank you in advance.
OK, so I am sharing a possible solution. I think the problem could be the vertical GPU mount by Cooler Master. In my BIOS settings, I had set it to PCIe 3.0 and not 4.0, coz it doesn't support that. Maybe somehow it got reset and that was causing it. So here's what I did:
- Clear CMOS
- I put my Graphics card directly into the motherboard and it booted fine.
- I updated the BIOS, just to make sure the old version wasn't causing all the problems.
- I changed the PCIe settings to 3.0
- Mount my GPU vertically again.

And it's working so far. I'll be testing it out for some days and see if the problem returns. If it does, I'll test it without the vertical mount for some days just to double check.

Leaving it here just incase it helps someone.


Posts: 1,814   +296
Could it be that the psu is on the way out? You said it was 7 years old. When my PC got temperamental about starting I thought motherboard or psu. The motherboard looked OK (no dodgy looking capacitors) so I replaced the psu. I made a lucky guess.