Question My system shut down without warning and now flickers on and off when attempting to start.

Kolbe Howard

Oct 19, 2015
I built my system in 2015 with an i7-4790k and an Asus Z97-A motherboard. Since then I've made a couple revisions but in the last few months a few components have had to be replaced. About 6 months ago the power supply died and I replaced it so I'm pretty sure this isn't the issue. A few weeks ago my AIO Cooler died and I replaced it with a Be Quiet air cooler.

Today I was doing nothing particularly intensive working on a google doc and my computer shuts down without warning. When I attempted to turn it back on, during the boot process I noticed that the CPU led light was lit up and the system was hung up and not going to BIOS. This has never happened before. I restarted the computer again and now the lights will turn on and the fans will run for about half a second and the it shuts off. Then a few seconds later the process repeats infinitely

I've since unplugged the PSU for a few minutes and plugged it into the wall since my UPS is also very old and I wanted to make sure it wasn't the issue, but it resulted in the same problem. I reset the CMOS and that did nothing either.

Could this be CPU or motherboard failure? Both are just over 5 years old. The CPU has been lightly overclocked for the past years but nothing extreme. I was planning on upgrading my system in a few months but money is tight at the moment and I really don't want to have to replace the Motherboard CPU and Ram if I didn't have to.

Edit: Power supply is a Be Quiet Dark Power Pro 650w. And I have 16 gb DDR3 ram. I should also mention that my boot drive is a 250 gb Samsung Evo SSD and it's also 5 years old.
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Could you post all system components.

In cases like that, CPUs are rarely the issue.
In most cases is either the motherboard, RAM or the PSU.

I have seen brand new PSU cause similar issues.
What's your PSU make and model?