Computer fans and fan led lights turn on and off while computer is powered down

[3MP]

Hi Folks,

Last week I was on my way to bed when I heard what sounded like a turn signal in my house. I looked over at my computer (which I had left powered off), and saw that the case fans and cpu fan (along with their led lights) were powering on and off. I tried to power on my computer while this was happening, and the computer didn’t boot. So I powered down the psu via the switch on the psu, and after the fans powered on and off about 5 more times, they stopped. I turned the psu back on and got the same result. So then I shut the psu off again, shut off my power strip that the computer is plugged into, and went to bed.

The next day I woke up ready to troubleshoot my computer, but turned on the power strip and psu, and found that my computer was silent. So I powered on my computer, and it worked perfectly fine.

Yesterday, while my computer was powered off, I was on my way to bed, and heard the turn signal sound again. So I flipped the power switch on the back of the psu again, and went to bed. Today, I flipped on the psu power switch, and the computer was silent. So I hit the power switch on my computer case, and the computer powered on like normal. Since the computer is powered off when it occurs, my thought is that it’s the psu, but since the problem doesn’t occur continuously, I’m not really sure if I can troubleshoot the problem at this point. Note sure if I should just wait and see if the problem worsens/persists, pull out the psu and stick my old one in there for a few weeks to what happens, or send the psu in under the warranty. I was hoping to get some thoughts on what the problem could be or any suggestions as to what steps to take please.

I built the computer myself over the course of a couple of years. Here are the specs and the approximate dates when purchased/installed (please note that the computer has not been overclocked):

Intel i5-3570k (about 2 years ago)
ASRock z77 pro4 motherboard (about 2 years ago)
Zalman cpu cooler (about 2 years ago)
WD Raptor HDD (installed about 2 year ago, but about 10 years old)
Samsung EVO SSD (about 1 year ago)
Thermaltake Overseer RX-4 computer case (about 1 year ago)
Gigabyte GeForce 770 4gb (about 1 year ago)
Corsair HX850 psu (about 8 months ago)

Thanks in advance for the help.

 

[Dogsnake]

Before you disassemble try removing the system from the power strip and plugging directly into the wall outlet. When the system is shut down not entirely off by Windows. There are usually L.E.D.'s lit on the MB indicating power. Are you using a power battery back up or just a strip? If using the wall outlet fixes the issue then it is likely the strip is at fault. If not then I would think PSU. You might try a different wall outlet as well.

 

[3MP]

Thanks for you reply Dogsnake. I'm currently just using a power strip (and not a power battery back up). The other devices that I have plugged into the power strip seem to function normally while the computer isn't, but perhaps there is an issue with the power strip (or outlet) and the computer is just reacting while the other devices aren't? It's definitely worth a shot though, so I'll see if I can set my computer up at a different outlet with a different power strip soon. Thanks again for your help.

 

[Dogsnake]

I suggest you not use a power strip for the first test. I things improve then try with the second strip.

 

[3MP]

Sounds good I'll give that a shot then, thanks again Dogsnake.