B850m suddenly dead

The CPU can trigger a power safety and prevent power on yes, if something inside
the CPU has shorted out. If a power safety has triggered for another reason and
not cleared it can also cause the system to not respond to the power switch. You
can try the following to rule that out:

1. Disconnect the system from power
2. Disconnect the PSU from the board
3. Disconnect power from all devices attached to the board
4. Leave the system in this state for a few hours (I usually leave it over night)

Then reassemble and see if the safety has cleared. If not then you can remove
the CPU to check if it has any obvious damage. It looking fine isn't a guarantee
that it's ok but it does rule out a more catastrophic failure. If the
system does not power on once you reinstall the CPU then I would begin the RMA
process for the CPU and possibly the board if it has taken any kind of damage to
the socket.

The known issue is exceedingly rare despite the media over focus. I have only seen
a small number of cases reported here on the ASRock official forums which should
be telling. The upside is, if you are one of the unfortunate few, the process of
getting it sorted should be pretty straight forward and not cause you any headaches
as AMD and ASRock are both taking the issue very seriously.

Good luck and let us know how it goes.


Edited by Xaltar - Yesterday at 12:29am

AFAIK the board won't power on without a CPU installed either.

I would contact your retailer (Overclockers UK) and ask what they recommend. In
all likelihood the board is absolutely fine. That said, it is your system and your
investment so if you feel uncomfortable using it with the replacement CPU then by
all means take whatever steps you feel you need to. From what I have been able to
piece together I suspect there is an issue with some AM5 9k series CPUs, possibly
bad batches or some such. ASRock seems to have had more failures but other manufacturers
have also had reported incidents so I highly doubt it is the actual boards, particularly
since there have been 0 cases involving the 7k CPU series on the same boards.

Ask your retailer what they would recommend/permit. I am sure they will have some
kind of policy in place for the issue. I suspect it will be fine with a new CPU
but if the CPU is from the same batch it may still be a risk.

This is an annoying issue for all parties, particularly since no one seems to know
or isn't saying what the exact cause is. My money is on AMD as if it were a single
board manufacturer no doubt they would have been thrown under the bus completely
by now. None of the board manufacturers would risk making AMD angry
however.

Edited by Xaltar - 15 minutes ago at 5:26am