X870 will not post after switching itself off

[Tetras]

Two faulty 9800X3Ds in a row though is surely reaching beyond improbable.

They are kind of "edge case" CPUs, at the bleeding edge of technology and in high demand (which might tempt them to make them faster and more of them, than perhaps is justifiable).

Though, one could argue AMD have had more than enough time to make these properly, because the X3D has existed for a long while.

Was EXPO enabled for the duration in both cases?

 

[Jerome]

Was EXPO enabled for the duration in both cases?

Yes, EXPO enabled both times. I always used the latest (non-beta) BIOS versions.

If I recall correctly, EXPO was also enabled for the vast majority of the time I had the 7600X as well. It's also enabled now with the new 7800X3D installed.

I hadn't noticed any strange thermal or voltage issues with periodic monitoring on the latest 9800X3D. It could also be purely coincidental that they each lasted roughly one week.

One key point to note is that both seemingly died while the computer was completely idle. In both cases I was out of the room and came back to it. In the first case, the computer had turned itself off completely and in the second case, yesterday, the screens didn't wake when I pressed buttons on my keyboard/mouse but the PC itself was still running. I rebooted it via the reboot button and it subsequently failed to post.

I decided to enable EXPO again with the 7800X3D as I want to replicate the conditions which led to the failure of the 9800X3Ds. If it occurs with the 7800X3D then it can be concluded the motherboard is the major suspect and I can then justify spending out on getting a different model.

On the plus side, fitting a new CPU/cooler was a daunting task as a first timer but I feel mighty comfortable by this stage.

I've seen quite a few posts around the internet about 9800X3Ds failing here and there but I haven't seen any 'two in a row' cases besides my own as of yet. Time will tell.

 

[Tetras]

I decided to enable EXPO again with the 7800X3D as I want to replicate the conditions which led to the failure of the 9800X3Ds. If it occurs with the 7800X3D then it can be concluded the motherboard is the major suspect and I can then justify spending out on getting a different model.

I'm only asking because the use of EXPO was part of the early burning issues with the 7800X3D and AMD introduced a voltage cap that was pushed out in the fixed BIOS of first gen boards. I would think it unlikely that this issue has occurred again, since any second gen boards should maintain those fixes, but different boards/manufacturers do have different behaviour.

 

[Jerome]

I'm only asking because the use of EXPO was part of the early burning issues with the 7800X3D and AMD introduced a voltage cap that was pushed out in the fixed BIOS of first gen boards. I would think it unlikely that this issue has occurred again, since any second gen boards should maintain those fixes, but different boards/manufacturers do have different behaviour.

Makes sense. I also thoroughly checked the pins/contacts on the second failed CPU and no visible signs of scorching or damage. I know there was talk a couple of months ago about an MSI board burning out an 9800X3D but that was deemed to be an incorrect seating which lead to it.

 

[Tetras]

Makes sense. I also thoroughly checked the pins/contacts on the second failed CPU and no visible signs of scorching or damage. I know there was talk a couple of months ago about an MSI board burning out an 9800X3D but that was deemed to be an incorrect seating which lead to it.

It does sound like the CPU had a problem internally, rather than the board killing it.

FYI: the burning issue did not apply to any non-X3D CPUs.