New power supply causes PC to restart when it wakes up from sleep.
New power supply causes PC to restart when it wakes up from sleep.
I changed my power supply last night because the fan was making a loud noise due to a worn bearing. I replaced the EVGA 750 Supernova SFX with a new Cooler Master v850 SFX unit. Everything functioned smoothly until I powered off and then restarted my PC. When I turned it on this morning, I saw the system briefly spun the fans before booting up as if it had been in sleep mode instead of power-off. I repeated this test several times and noticed the issue each time I tried to wake from sleep. The video is linked below, along with an MP4 file attached.
Have you consistently relied on wake from sleep? Did you review your power configuration to confirm no adjustments were made and that Windows is intended to resume operation from sleep rather than restarting? What information does the event log provide?
This problem originally appeared on a friend's PC. I didn't fully grasp it at first. I thought certain motherboard/PSU combinations couldn't handle all power modes. We managed by turning off lower power sleep settings in the BIOS, ensuring the mainboard maintained a baseline PSU load during sleep. Could be worth trying. Another option is using hibernation instead of sleep, accepting slightly longer wake-up times.
I've consistently used sleep mode instead of shutting down fully—just a routine that developed when booting from an HDD took over 15 seconds. Experimented with different power settings but haven't noticed any improvement. Also reviewed system activity in Event Viewer, and the logs show it's logging into sleep mode before powering on. Honestly, I'm not sure what's going on.
I believe I should start using hibernate. It won’t be a huge change—every time I reach the Windows lock screen it now takes under five seconds. My Acer ultrawide screen also takes that long to wake up from power-saving mode, so the overall experience hasn’t improved much.
I encountered an issue after changing the power supply unit. The new one is a Thermaltake model, while the old one was a Gigabyte unit. I tried using YouTube or Netflix in a Chrome tab during sleep mode and didn’t notice any problems. I’m trying to remember this workaround. Eventually, I might need a wired keyboard to check the BIOS settings for adjusting sleep power levels.