Question PC randomly goes into low power (sleep/hibernate?) mode

Dec 17, 2019
Hi everyone, first time poster long time follower here.

Last summer I put together my first build ( and it has been running great until about 2 months ago where I've started encountering this odd issue that I've tried everything in my power to diagnose/resolve.

My machine seems to randomly go into a sleep/hibernate/low-power mode (I can see the RAM lights remain on) and all fans turn off, pressing the power button does nothing, holding the power button does nothing. I have to manually flip the power supply, wait for power to cycle, flip it back and turn on the machine, where it turns on like nothing happens.
  • This has happened over 30 times at least
  • Whenever it happens and I restart it tends to happen again within the next few minutes most of the times when opening another program but sometimes randomly
  • A couple of times only instead of the above I got a "Boot drive not detected message", after clicking random keyboard keys the machine restarted by itself into windows.
  • Some days I run for hours under heavy load and nothing happens, some days this happens 6-7 times in a row and I get frustrated and step away
Things I've tried/checked in random order:
  • Checked windows error logs
    • No related error codes appear apart from the ones relating to me flipping the power switch as mentioned above
    • Bug Check codes are zeroes for errors related to shutdowns
  • Ran windows memory diagnosis to check RAM
  • Ran some form of disk checkers (can't remember the software name) for my SSD and HDD
  • Checked motherboard voltages in hardware monitor and in BIOS
  • Turned off GSYNC
  • Tried safe mode (issue still happened in safe mode)
  • Tried moving my GPU and SSD to other slots
  • Checked GPU/CPU/Drive temperatures
  • Increased fan speeds
  • Reinserted my RAM
  • Moved GPU to another port on my power supply
  • Uninstall graphic drivers with DDU and installed a driver for my gpu from April before my issues started
  • Scanned for malware with Malwarebytes
  • Scanned for rootkits with TDSSkiller
  • Made sure windows was up to date at some point
  • Disabled XMP in BIOS
  • Messed with windows sleep settings to make sure it never sleeps on it's own
  • Tried disconnecting all peripherals except Keyboard/Mouse/Display and issue still happened
  • Tried using a different monitor (a TV), issue still occured
I'm really feeling desperate here and would appreciate any advice/help