Asrock Taichi x370 + 5800x Upgrade: no post and er

I am running Asrock Taichi x370 & 1800x and was looking forward to upgrading the CPU to 5800x.

Unfortunately, replacing the CPU results in a dreaded boot cycle loop & the error code LED remains blank. Of course, this means I cannot even get to the BIOS.

When I put the 1800x chip back in, everything works like a charm again.

So far, I've done the following before replacing the 1800x with 5800x:

- Upgraded the BIOS to 7.04 (currently the latest)

- Cleared the CMOS via the button in the back of the mobo, jumper, as well as removing the battery for at least 4 hours

- Restore the BIOS settings to default (be sure not to use XMP profile)

- Use just 1 out of the 2 DDR4 2133 RAM (16GB each) sticks and in different slots (A2, B2, A1, etc.)

- Removed all the extra drives except the NVME startup SSD running Windows 10

What am I missing? Could the blank error code LED mean I have a bad CPU? Any help would be much appreciated!

I did see this, X370 Pro4     7.20     04/26/2022     04/29/2022,
so, I assume we need to wait for 7.20 to come to the X370 Taichi board.

kerberos_20 wrote: bios 7.10 is there, use that one https://www.asrock.com/mb/AMD/X370%20Taichi/index.asp#BIOS

Oh, nice, they just released that a few days ago.

Elkadillo wrote: Did you ever find a solution? I'm on 7.10 on the Fatal1ty Professional Gaming. Works with a 1700 but won't post with a 5800X.

No, but my problem is different, I do not have access to an older CPU to flash so I am stuck.