Solved 3 year old setup booting issue | Motherboard/CPU/PSU at fault?

short disclaimer: a bit inexperienced with troubleshooting hardware issues, I'll try to keep an eye out for missing details and update accordingly.

Build/component list is given at the bottom

Current issue summary:

• Computer does not boot

• Motherboard does not change status code from 00, wheras normally it would cycle through several and end up on the successful boot code.

• Motherboard still gives power to USB units, but does not properly activate them

• Suspected causes:

• CPU dead? (starting the computer with the CPU plugged out of the PSU results in the same 00 error code on the motherboard)

• Motherboard dead? (CPU does gain power, as its temperature increases during boot attempts, but could something else be wrong with it?)

• PSU issue? (Everything seems to be getting power, could the PSU still be at fault?)

I have done a decent eye-check of both these components and cant seem to find any visible signs of damage from overheating or the such, but I may not have an experienced eye to catch these well enough?

Earlier symptons:

• Computer would boot inconsistently: right away, after a few restarts or after several restarts.

• Monitor screen is black

• USB devices seemed to gain power, but would not properly activate (keyboard/mouse would normally light up, but dont. External harddrive lights up and starts "spinning", but in an irregular way compared to what would happen during a successful boot.)

• Suspected causes during times of early symptoms:

• BIOS issue

• BIOS battery issue? (time/clock never reset during early symptom days, so have dismissed this)

• Driver issue (updated various drivers, but never got to update BIOS as it seemed like a bit of a time investment/risk at the time)

• PSU issue (checked some voltage measurements available in BIOS, which seemed in line and consistent, but may have been different during loaded tasks?)

Some of the things I have tested thus far:

• Swapping RAM positions

• Plugging/Unplugging cables connected to the PSU/motherboard.

• Unplugging GPU

• Boot attempts with/without various components plugged in/out: usb units, bios-battery, gpu, cpu, cpu-fans..

• pleading to every diety in the universe to show me mercy

Thoughts about future:
It seems likely motherboard and/or cpu is whats causing me trouble, so it seems likely that swapping one or both of those may be a solution? If I'm swapping one of them I may end up swapping both, so that I can go for an upgrade, i9-9900k + asus z390-f strix seems compatible and promising? Though there is always the chance the issue lies elsewhere, potentially the PSU? Please help.

History:
The last quarter my desktop has encountered issues with booting up. I have usually shut down my computer before going to sleep, and booting it back up in the morning. Come autumn 2019 my computer would occasionally not boot up (monitor screen black, USB units not activating properly). The motherboard would cycle through and display status codes, and then stop on an error code (I have forgotten which code it specifically ended on these times). Additionally the fans would be very loud right away and stayed that way until the computer was shut down.

From there booting up became inconsistent. Sometimes it would start up right away without any issues, other times it would take several restarts before it would randomly start up, but after however many restarts it always did boot back up. As long as the computer was kept on it suffered lack of performance at all, it ran as smoothly as ever.
In december the computer was not shut down for 1-2 weeks, because I was too reliant on the computer at the time and on a tight schedule, before finally turning it off and plugging out power before leaving for a 2 week holiday.

Now, just back from holidays, the computer does not boot at all.


This was my first complete pc build, the components were ordered, and the build assembled, in October 2016. I have had no problems for 3 years, until this booting issue came up

Complete build pcpartpicker-link

Component list: included are product-links for each component, from the site I ordered them (note: norwegian)

Case: Fractal Design Define R5
Motherboard: ASUS ROG MAXIMUS VIII HERO, Socket-1151
CPU: Intel Core i7-6700K Skylake
Cooling (CPU): Noctua NH-D15 CPU
RAM: Crucial Ballistix Elite DDR4 2x8gb
SSD: Samsung 950 PRO 256GB M.2 PCIe SSD
GPU: ASUS GeForce GTX 1080 ROG Strix Gaming
PSU: EVGA Power Supply 650W GOLD
OS: Microsoft Windows 10 Home

Additional notes/details:

• Monitor is connected by displayport

• I generally just keep 3 usb units plugged in: keyboard, mouse, headset. Ocassionally an external harddrive.

• Thermal paste: Noctua NT-H1 (last applied between CPU/CPU-Cooling during assembly)
  
  

Thank you if you made it through!

phillpower2 said:

Welcome to PCHF OpenCasket,

Can I just ask, by unplugging GPU do you mean actually removing it from the MB or leaving it in and just swapping the video cable to the appropriate one on the MB.

Click to expand...

I removed the GPU entirely and then connected the screen to the motherboard.

I've also asked around on some other forums, and it seems likely that the PSU is the culprit. The PSU fan is not spinning during the boot up regardless of wether the eco-mode is on or off, only stuttering briefly as the system is shut down. There is a slight burnt smell emitting from it, nothing substantial, but for now I'll try replacing it and see if it solves my issues.

phillpower2 said:

Any update for us?

Click to expand...

Hi, replaced the old PSU with a new one of identical model, the PSU fan is spinning now, however the booting issue remains unchanged.

Does this leave the motherboard/cpu?

phillpower2 said:

Can I as what the outcome of testing the original PSU was.

Click to expand...

PSU fan still didn't spin, unlike the new one.

Wrapping this up:

Decided to bite the bullet. Motherboard and CPU have been replaced, computer is now booting up nicely, and performance is great. So either/both of those should have been faulty.

I plan to order something to measure the stabillity of the electricity in my home, in case that could have played some role in why my components went bad, as to avoid something similar happening again.

Thanks again to all who've invested time into helping me resolve this! It's really nice to have a place to reach out to whenever you encounter issues like these

About the replacement:
I decided to go for an upgrade rather than just replacing them with identical models. Processor is now an i9-9900k and motherboard is an asus z390-f.