Question Computer experienced severe slowdown. Won't turn on after reboot.

[spzero]

I built my gaming computer about 2 months ago and everything was running smoothly until last night. After an hour of playing a game (Hitman 2), I experienced a massive slow down in my whole system. Framerate dropped from 70FPS to about 3FPS then everything else became relatively unresponsive. I was able to close my game but the problem of slowness continued while in desktop. Performed a hard reboot and and it took almost a minute or two for the screen to work and it basically got stuck at the bios/boot selection screen. After another minute or two in that page, the screen went black and continued black. Rebooted once again and this time I could not even get anything to appear on screen. Some of my motherboard LEDs used to light up but after doing my 2nd reboot, they do not do so anymore.

Here is what I am running:

CPU: Intel - Core i9-9900K 3.6 GHz 8-Core Processor
CPU Cooler: Noctua - NH-D15 82.5 CFM CPU Cooler
Motherboard: Gigabyte - Z390 AORUS ELITE ATX LGA1151 Motherboard
Memory: Corsair - Vengeance LPX 16 GB (2 x 8 GB) DDR4-3200 Memory
Storage: Western Digital - Blue 500 GB M.2-2280 Solid State Drive
Storage: A couple of older HDDs
Video Card: Gigabyte - GeForce RTX 2080 Ti 11 GB AORUS XTREME Video Card
Case: Fractal Design - Meshify C ATX Mid Tower Case
Power Supply: EVGA - SuperNOVA G3 750 W 80+ Gold Certified Fully Modular ATX Power Supply
Operating System: Microsoft - Windows 10 Home Full - USB 32/64-bit

What I've tried:
I've disconnected the GPU and tried running the computer through integrated graphics and no luck. I've also shifted around and tried single memory sticks (and no memory sticks) and checked for bent pins and rechecked connections to my power connections to my motherboard and CPU. I've also tried resetting CMOS and tried to boot through a different BIOS setting.

Currently when I turn my PC on the fans, HDDs/SSDs, and GPU all light up and make noise. My motherboard's status LEDs would stay red on the DRAM light though during the first second or two of start up, the CPU would flicker but when then immediately change to the DRAM and stay solid there. However, I do notice that when I immediately turn it on, after a second or two it would shut down and do a quick reboot before seeming to hold the power on the 2nd boot. Furthermore, aside from the XMP, I do not overclock anything else on my computer.

Can anyone help?


EDIT:

An update - the motherboard failed. Everything else worked fine on a test motherboard and a new replacement.

 

[clarkjd]

After turning the PC off and letting it cool down (say overnight), do you experience the slowdown when you boot first thing? Are you sure your CPU cooler is still firmly attached to the CPU?

 

[spzero]

After turning the PC off and letting it cool down (say overnight), do you experience the slowdown when you boot first thing? Are you sure your CPU cooler is still firmly attached to the CPU?

The slowdown does not occur anymore. At this point, it's just not booting up to BIOS. I also left it overnight to cool off since the problem started last night.
And I reseated the CPU and reattached the cooler and the nothing has changed.

 

[clarkjd]

The slowdown does not occur anymore. At this point, it's just not booting up to BIOS. I also left it overnight to cool off since the problem started last night.
And I reseated the CPU and reattached the cooler and the nothing has changed.

Sounds like either the motherboard died or the CPU is gone(or both!). Unfortunatly, you need one or the other working to confirm the bad component. That being said, Its been my experience that motherboards are more prone to failure than are CPUs.

 

[spzero]

Sounds like either the motherboard died or the CPU is gone(or both!). Unfortunatly, you need one or the other working to confirm the bad component. That being said, Its been my experience that motherboards are more prone to failure than are CPUs.

Thanks. I've just went out to get a replacement RAM stick and it does seem like it's either the CPU or motherboard at this point. Guess I'm out of luck.

 

[clarkjd]

If you haven't already, you might attach a speaker to the system speaker output (NOT the audio outs!) and see if you get any beep codes. That might give you more information as to which component is failing.