Gigabyte z370n won’t even POST

[sqweak]

Been trying for a week to get a new hackintosh build together, and I’m at my wits end.

Gigabyte z370n
8700k
Corsair h105
Corsair vengeance lpx 16gb 2400
Samsung 960 evo 500gb nvme
Corsair rm550x
Fractal design meshify mini

It turns on, ramps up and then down, and just sits there. No power to keyboard, no output, no bios, nothing. It’s stable and doesn’t reset (like it would without ram or cpu) Here’s a video

Once the other night, it booted to bios. When I found my boot usb and restarted I could never get it back again. Then tonight, I got a string of 3-4 successful boots in a row. During one of those, I found a bios setting that was defaulted to “output video via pcie” and changed that to igfx. A few reboots worked, and now I’m back to the same behavior.

I’ve reseated and rebuilt the whole thing a dozen times. Swapped out components. No change. I even swapped everything into another motherboard (same case, psu, cpu, cooler, ram, everything) and it booted up first try with no issues. After all that I exchanged the z370n with amazon only to get the exact same behavior from a new board.

Do I just have bad luck, or am I doing something wrong?

 

[P1LGRIM]

Gigabyte z370n
8700k
Corsair h105
Corsair vengeance lpx 16gb 2400
Samsung 960 evo 500gb nvme
Corsair rm550x
Fractal design meshify mini

I see that there is no Corsair 2400 RAM on the QVL, are you sure that it is compatible ?

 

[sqweak]

I see that there is no Corsair 2400 RAM on the QVL, are you sure that it is compatible ?

Incompatible ram wouldn’t stop it from POST and showing bios, would it?

Regardless, this QVL lists CMK16GX4M2A2400C16 and 20 other Corsair 2400 as compatible.

 

[P1LGRIM]

Incompatible ram wouldn’t stop it from POST and showing bios, would it?

Yes, RAM is a requirement to POST.

Regardless, this QVL lists CMK16GX4M2A2400C16 and 20 other Corsair 2400 as compatible.

My bad then.

 

[sqweak]

My bad then.

No worries, appreciate the thought!

The same behavior with other compatible ram (skill trident z 3200), and the very (very) sporadic successful boots make me think it’s not the components but a setting/bug/issue with mobo itself

 

[Adrian B]

If you have a case speaker then attach it to the correct connections on the board and check which beep codes that you are getting.
https://www.gigabyte.com/Support/FAQ/816

Are you running the latest UEFI/BIOS?

Edit - disconnect the reset connections from the board and see if you see a change.

 

[sqweak]

If you have a case speaker then attach it to the correct connections on the board and check which beep codes that you are getting.
https://www.gigabyte.com/Support/FAQ/816

No case speaker

Are you running the latest UEFI/BIOS?

Board is fresh out of the box. Not sure how I could update bios when it’s so sporadic at booting?

Edit - disconnect the reset connections from the board and see if you see a change.

No change, even with only power switch (no reset, pwr led, hdd led, fpanel usb, fpanel audio) connected

 

[Adrian B]

Do you or a friend/neighbor have an old case with a PC speaker that you can use for some quick testing.
The audio beeps would really help to narrow down if it is RAM, CPU, GPU, PSU or something else.

 

[sqweak]

Do you or a friend/neighbor have an old case with a PC speaker that you can use for some quick testing.
The audio beeps would really help to narrow down if it is RAM, CPU, GPU, PSU or something else.

Bought a motherboard speaker at fry’s...I get exactly 0 beeps

Update: it just did one of its rare successful boots, and beeped once, so I know the speaker works at least

 

[sqweak]

Why was this moved to post-install? Shouldn’t a build issue be in the build forums?