[SOLVED] Motherboard gone?

[anvoice]

Hi, have an Asus ROG Crosshair VII Heron wifi-based PC that worked fine until recently. A few days ago, the system started freezing, and stopped booting to my on-board NVME disks. Today, it stopped posting altogether. The last postcode it's on is either "8" or "B", with a blank following it. I'm not sure what this means since the official postcodes all have either 2 digits or a letter and digit. Also, the computer will not hard-reset at all, I have flip the PSU switch to get it to shut down. All fans (CPU and case) are spinning. I'm guessing my motherboard is gone, but was hoping someone might weigh in with their thoughts.

What I've tried:

• Replacing RAM with a known good stick
• Removing graphics card
• Flashing a new BIOS twice

System specs:
OS: Windwos 10 Pro
MOBO: Asus ROG Crosshair VII Hero wifi (x470)
CPU: Ryzen 2700X
RAM: G. Skill Ripjaws V 3200MHz 32GB
HDD: 2x Samsung PM981 512GB NVME
GPU: Geforce GTX 1070
PSU: Seasonic Prime Titanium 650W

 

[Lutfij]

Which BIOS version are you currently on for your motherboard? You forgot to to mention the make and model of your PSU and it's age. Which version of Windows 10 were you working with prior to the mishap? Make and model of the ram is also missing. Which slots are the ram sticks populating?

 

[anvoice]

Thank you, updated the specs. My Seasonic Prime Titatnium 650W PSU is less than two years old. I've also tried an older RAM stick (16GB in slot B2, where it worked fine for over a year) as well as the new kit I got recently (2 16GB sticks in A2 and B2, as per instructions in the motherboard manual).

If the fact that when I updated the BIOS earlier, the update LED blinked for a couple of minutes and then stopped is any indication, I should be on version of the BIOS 3103 (latest). Also was working with Windows 10 Pro.

 

[helpstar]

use one RAM in slot A2

the graphics card has to be installed, the CPU doesn´t provide an integrated GPU, so that the motherboard video ports won´t work at all, but that´s normal. Usually the system will activate the GPU LED on the motherboard and won´t post/boot if no GPU is installed or under powered (white LED)

other LEDs
green -> boot device
red -> CPU
yellow -> DRAM

Remove the SSDs/HDDs and all other unnecessary devices (wifi,...)
only use:
motherboard, PSU, GPU, CPU with cooler and fan, one RAM (try all slots and RAM you have, one stick at a time)

reset the BIOS by jumper/clear CMOS button

 

[anvoice]

Looks like that was it (by that I mean some combination of things in your answer). Specifically, I plugged in the GPU and removed all devices as you suggested, and got it to POST and boot into BIOS. Started adding back hardware: it was the SATA SSD that was bricking the board. I have no idea how that works, but as long as it is connected, the motherboard will stop at the "8" postcode and never gets to BIOS, and cannot be hard-reset. I believe this answers my question, so I will get back to attempting to salvage my data which was on the two NVME drives which lost their RAID 0 configuration during this whole malfunction... Thanks a lot!

 

[anvoice]

And as much as I hate to ruin a happy ending, the mobo is busted again. Computer shut down while trying to recover data from my SSDs. Same "8" postcode now no matter what I do. Swapped PSU, problem persists. Looks like I'm out a mobo.