[SOLVED] No boot, no POST, went through checklist

[broodling123]

Hi everyone,

I’m losing my mind here - hopefully you all can help!

For the last few months or so my 3 year old PC would have significant difficulty starting up. Once it was running it was fine, but every time it got turned off it would get stuck in a boot cycle with no POST, then finally start up after 5-10 minutes of cycling. Last week it finally died, and won’t boot at all. I have been trying to diagnose the problem for a week now with no luck.

I took the whole computer apart, reseated everything. Went through the stickied checklist. Disassembled down to a barebones system (CPU, cooler, mobo, PSU, one memory stick), still no dice. I have tried replacing both the motherboard and the PSU, but still get the same result. The AIO seems to be running (replaced the fan as it was getting noisy) and the pump (can hear it running occasionally). Tried loosening the fasteners for the cooler slightly. No scorch marks or signs of damage on the CPU as best I can tell.

Part list:

• Gigabyte Z390 AORUS Pro Wifi Motherboard (new)
• Intel i7 9700K CPU
• EVGA Supernova 650 G3
• Corsair H60 AIO CPU Cooler
• G.Skill Ripjaws V Series DDR4-3200

I can post the rest of my components as well, but since I can’t even get the computer to POST with this setup, it seems unlikely that those would be relevant.

This isn’t my first build, but I’m by no means an expert at this. Do you have any ideas why this might happen?

 

[Nine Layer Nige]

There maybe a CMOS reset for your Mobo by removing the CMOS battery for x seconds or perhaps some reset jumpers on the board to set/reset (a little plastic topped thing that you pull of and then place onto the next jumper prong (of 3) on the board.)
It may be marked CLR_CMOS on the mobo.

Page 24 of your manual...
Section 21) CLR_CMOS (Clear CMOS Jumper)
Use this jumper to clear the BIOS configuration and reset the CMOS values to factory defaults. To clear
the CMOS values, use a metal object like a screwdriver to touch the two pins for a few seconds.
• Always turn off your computer and unplug the power cord from the power outlet before clearing
the CMOS values.
• After system restart, go to BIOS Setup to load factory defaults (select Load Optimized Defaults) or
manually configure the BIOS settings (refer to Chapter 2, "BIOS Setup," for BIOS configurations).

 

[broodling123]

@Nine Layer Nige Thanks for the feedback. Tried clearing CMOS on both the old and new board both using the jumper and removing the battery. No luck there either.

 

[Nine Layer Nige]

Is it possible that the motherboard is shorting out on the case somewhere. Try removing mobo and running on table not in case

 

[broodling123]

I haven’t even tried the new mobo in the case yet. Currently have it hooked up to my backup PSU on a cardboard box on my desk. Have been doing all of my testing there.

 

[Nine Layer Nige]

Last thing I can suggest is borrowing a different 9th gen cpu to try, but I know how difficult that can be.

 

[broodling123]

Quick update - this ended up being a dead CPU. Replacing the CPU resolved all issues. Thanks for the help!