Motherboard CPU debug light flashes before immediately turning off, no display

[Rabbit]

I've replaced my CPU and motherboard based on something which previously affected my PC, however even with the replacements I'm still getting nothing. I've tried power cycling as well to no avail.
My specs are:
- MSI Z370 PC-Pro
- Nvidia 1060 GTX
- Intel i5-8400
- EVGA 500W Bronze
- DDR4 8GB x 2
- 2TB HDD

[Electric Cupcake]

What does your motherboard manual say about the flash code?

[r.linder]

As Hugsie said, check your motherboard's manual.

Preemptively unplug all cables from the motherboard and plug them back in.

[Rabbit]

Originally posted by Hugsie Muffinball:

What does your motherboard manual say about the flash code?

There's nothing about the specific way it flashes, however I'm led to believe it'd be a solid light if the power didn't completely shut off for the computer after a split second. The fans begin to turn and the motherboard lights up as it normally would, but it never gets anywhere or displays. The only thing the debug lights do is flash CPU, then turn off as soon as everything else does.

Originally posted by Escorve:

As Hugsie said, check your motherboard's manual.

Preemptively unplug all cables from the motherboard and plug them back in.

Trying this now.
Edit: did this, no changes.

[_I_]

use the jumper to reset bios to defaults
(JBAT1) jumper above the pci-e x4 slot (x4 electrical, x16 length)

boot to bios if it can, then reset to defaults in bios

set xmp profile to whatever the ram has

the z board may be able ot fake it as a k cpu and oc, but it was not binned as a k so oc will not be as good as k

[Rabbit]

Originally posted by _I_:

use the jumper to reset bios to defaults
(JBAT1) jumper above the pci-e x4 slot (x4 electrical, x16 length)

boot to bios if it can, then reset to defaults in bios

set xmp profile to whatever the ram has

the z board may be able ot fake it as a k cpu and oc, but it was not binned as a k so oc will not be as good as k

It wasn't able to boot to bios

[_I_]

reset bios first using the jumper

[Rabbit]

Originally posted by _I_:

reset bios first using the jumper

I did. It wasn't able to boot.

[Carlsberg]

sounds like you may have a short, strip machine and make sure board is clean,(no stray bits stuck to it), check all MB standoffs and re-assemble. Double check everything as you go, ensure slots are clean and there is no interference at standoff points etc. Test boot before plugging in any peripherals, and connect one at a time testing each.

[_I_]

try minimums

no dedicated gpu, 1 dimm, no usb, no drives or other devices

psu, mobo/cpu/1 dimm, display into the mobo, k/m only

(pull the mobo, make sure only the standoffs the mobo has mounts for are used)

[Rabbit]

Sorry for disappearing, I decided I had enough last night and headed off to bed. Tried some of the new suggestions this morning.

Originally posted by Carlsberg:

sounds like you may have a short, strip machine and make sure board is clean,(no stray bits stuck to it), check all MB standoffs and re-assemble. Double check everything as you go, ensure slots are clean and there is no interference at standoff points etc. Test boot before plugging in any peripherals, and connect one at a time testing each.

Originally posted by _I_:

try minimums

no dedicated gpu, 1 dimm, no usb, no drives or other devices

psu, mobo/cpu/1 dimm, display into the mobo, k/m only

(pull the mobo, make sure only the standoffs the mobo has mounts for are used)

I decided to run the motherboard outside of the case, with minimums. My case is a little bent so I figured maybe that had caught up with it, however even this didn't get the PC to run at all. Same as I've been getting, a blip of power before it shuts off completely, CPU light again. I'm using a replacement motherboard I just received as well, which was tested and approved by the manufacturer. I'm beginning to believe the PSU might be at fault, however I'm not a computer expert.
Update: tested PSU with a paper clip, seems to be dead.