Question Odd Computer Issue: Usually won't start

[ArtDeco3]

Hi! I am writing this from my computer that sometimes won't start. If I am lucky, it works. This is a computer originally from 2015. I built it myself. However, recently the motherboard died. I replaced it, and I had no problems for about 3 and a half weeks. After which, this issue began. Sometimes, the computer can not wake from sleep. Sometimes, all it gets is a spin of the fans for about half a second every time I try to turn it on. It automatically repeats around every 5 seconds. So, I took apart all the pieces and went for a breadboard test. Well, it worked.. so I added piece by piece and tested. However, sometimes, if I added a piece, and then subtracted the same piece, or even if I made no changes, the computer would not be able to start. I am really confused, and I have gone through the troubleshooting as best as I can, but I don't have a speaker.

Also, I have found that the only way to start the computer is to unplug everything and remove the CMOS battery, and then wait around 20 minutes. Resetting the CMOS had seemingly, no effect. The same is true of booting from the backup BIOS, and reflashing the UEFI, as well as changing and reverting many settings in the UEFI. I am totally confused! I also ran memory diagnostics multiple times, and I have cleared the test every time.

Specs:
Motherboard: AsRock z170 Fatal1ty Gaming K4
CPU: i7 6700K
RAM: G.Skill Ripjaws IV 3000 MHz, currently running at 2133MHz
CPU Cooler: Corsair H110i GT
PSU: Corsair RM1000i
SSD: M.2 Kingston A1000 240 GB boot drive
SSD: Samsung 850 Pro 1TB storage
Blu-Ray Drive: LG cannot find exact model info
GPU: Currently unplugged Zotac GTX 980Ti Amp! Extreme Edition

 

[Saga Lout]

One suspect for the spinning fan then stopping at boottime is the RAM sticks. Reseat it or them and see if the habit repeats. Swap them about until you find the one that might have caused it.

 

[ArtDeco3]

Sorry it took me so long to respond. Thank you for your response. I tried this multiple times now. Unfortunately, it wasn’t able to solve my issue. But I did learn something new.


As long as my GPU is not plugged in, if I don’t touch my computer for at least 20 minutes, then try to start it, it will try to enter the bios 2-3 times, and it will boot with no issues. However, usually I cannot wake the computer from sleep. The fans will spin for a half-second, then it will be completely powered off.

With the GPU in, the computers fans will only spin for a moment one time.
Whereas without it, it will try again and again around every 5 seconds.
Do you have any advice?