Question PC randomly stopped turning on, need assistance

Zombehh

Distinguished
Oct 2, 2014
210
0
18,680
About two months ago, I replaced my GPU and PSU. Everything was fine until a few days ago when I noticed my front CPU cooler fan lights were dim, with one only half-lit.

On Friday, I did an "update and shut down," left for the store, and when I came back, my PC wouldn’t turn on—no lights, no fans, nothing, as if it wasn’t plugged in.

I assumed it was the PSU, replaced it with a new one—same issue. Swapped the motherboard—still nothing. Unplugged the CPU cooler and GPU, spammed the power button, flipped the PSU switch, and at one point, the fans spun up for a few seconds but then stopped, and I couldn’t get it to happen again.

Things I’ve tried:

  • Replacing PSU and motherboard
  • Changing power cables
  • Jump-starting the power pins with a screwdriver
  • Holding the power button for 30s while unplugged
Specs:

  • CPU: Intel Core i7-13700KF (Thermaltake AIO Liquid Cooled)
  • GPU: MSI RTX 4060 Ventus 2X OC 8GB
  • Motherboard: Gigabyte Z790 AORUS ELITE AX
  • RAM: 64GB Corsair Vengeance RGB DDR5 6400MHz (2x32GB)
  • Storage: 2TB NVMe M.2
  • PSU: Thermaltake Toughpower GF A3 1050W (80+ Gold, ATX 3.0)
Could a dead AIO or CPU fan prevent the PC from turning on? Or is it the CPU itself? I'm out of ideas. Any help is appreciated.



Edit:

This happened from Reddit:

Redditor Comment:
From the off position, hold power button and reset button for 10+ seconds together to hard reset the bios.

Me:
Woah, so after doing that, fans and lights turned on, but then everything shut off after about 10 seconds.

I had the CPU cooler fan connected to the CPU_OPT and the CPU fans to CPU_FAN (I made this switch earlier when I was trying everything). And I only had 1 RAM stick plugged into the 3rd slot. I don't know if that had something to do with it shutting down. I am trying to repeat with everything plugged back in and hold the power and reset buttons, but it's no longer working.
 
Last edited:
If you've connected a new MB and power supply and turned it on without being in a case, and it Does Not turn on, then clearly either you've connected it wrong, or something is wrong with either the MB or PS.
I'll assume the following:
1-you have the CPU installed properly and no bent pins
2-you have memory inserted properly and in the correct slot(s)
3-no drives connected because it should POST and allow you into BIOS
4-KB and Mouse connected
5-the wall outlet has power
 
If you've connected a new MB and power supply and turned it on without being in a case, and it Does Not turn on, then clearly either you've connected it wrong, or something is wrong with either the MB or PS.
I'll assume the following:
1-you have the CPU installed properly and no bent pins
2-you have memory inserted properly and in the correct slot(s)
3-no drives connected because it should POST and allow you into BIOS
4-KB and Mouse connected
5-the wall outlet has power
i didn’t try the motherboard outside the case due to knowing that if i took everything out of the case i would have trouble putting it back in, however upon inspecting my PC i found these loose cables:
 
About two months ago, I replaced my GPU and PSU. Everything was fine until a few days ago when I noticed my front CPU cooler fan lights were dim, with one only half-lit.

On Friday, I did an "update and shut down," left for the store, and when I came back, my PC wouldn’t turn on—no lights, no fans, nothing, as if it wasn’t plugged in.

I assumed it was the PSU, replaced it with a new one—same issue. Swapped the motherboard—still nothing. Unplugged the CPU cooler and GPU, spammed the power button, flipped the PSU switch, and at one point, the fans spun up for a few seconds but then stopped, and I couldn’t get it to happen again.

Things I’ve tried:

  • Replacing PSU and motherboard
  • Changing power cables
  • Jump-starting the power pins with a screwdriver
  • Holding the power button for 30s while unplugged
Specs:

  • CPU: Intel Core i7-13700KF (Thermaltake AIO Liquid Cooled)
  • GPU: MSI RTX 4060 Ventus 2X OC 8GB
  • Motherboard: Gigabyte Z790 AORUS ELITE AX
  • RAM: 64GB Corsair Vengeance RGB DDR5 6400MHz (2x32GB)
  • Storage: 2TB NVMe M.2
  • PSU: Thermaltake Toughpower GF A3 1050W (80+ Gold, ATX 3.0)
Could a dead AIO or CPU fan prevent the PC from turning on? Or is it the CPU itself? I'm out of ideas. Any help is appreciated.



Edit:

This happened from Reddit:

Redditor Comment:
From the off position, hold power button and reset button for 10+ seconds together to hard reset the bios.

Me:
Woah, so after doing that, fans and lights turned on, but then everything shut off after about 10 seconds.

I had the CPU cooler fan connected to the CPU_OPT and the CPU fans to CPU_FAN (I made this switch earlier when I was trying everything). And I only had 1 RAM stick plugged into the 3rd slot. I don't know if that had something to do with it shutting down. I am trying to repeat with everything plugged back in and hold the power and reset buttons, but it's no longer working.
Hmm... Since BIOS reset briefly powered things up it could be a short/faulty CPU/ven RAM causing instability.

Have you tried booting with just one RAM stick in different slots or testing outside the case to rule out grounding issues?