Activate Windows 10 when OEM key is missing

We are offboarding a hundred plus Dell Latitude E7470 and 7480 model laptops by reimaging them with base Windows 10 Pro, and about a quarter of them fail to activate Windows 10 Pro due to not having a valid digital license.

I have found that following the guide here at dellwindowsreinstallationguide.com/the-oem-product-key-and-oem-system-locked-preinstallation/ shows the laptops impacted lack a MSDM field from BIOS.

I have additionally found I can predetect this devices using the following DOS command which, when successful, pulls the OEM key in BIOS/UEFI:

wmic path softwarelicensingservice get OA3xOriginalProductKey

We following a standard reimage over WDS/PXE for all the units, and units with the OEM key in the BIOS/UEFI activate fine, but others that do not fail.

I have also tried the Dell OS Recovery Tool at https://www.dell.com/support/home/en-uk/drivers/osiso/recoverytool, which actually checks the Dell serial against Dell's database and knows that it has a Windows 10 Pro License. Units that fail to activate via WDS/PXE, fail to activate using this tool to install as well.

Looking up the Dell Service Tag online, it shows that it came with Windows 10 Pro:

619-AHKN : Win 10 Pro 64 English, French, Spanish
PART NUMBER DESCRIPTION QUANTITY
025K3   SRV,OS,WIN10,64,MUI,E/F/S   1

Unfortunately, the devices I have on hand have left warranty support, I have detected one in warranty unit with the problem, but it's not currently available for me to work with.

After Dell servicing, we have been provided Dell paperwork for reactivating Windows that matches this image of the card. Ours are fresh and the seal is unbroken, reading:

W8P/W10 32/64BIT SVC DPK

These come with a Windows Product Key, but these also fail with:

We can't activate Windows on this device because you don't have a valid digital license or product key. If you think you do have a valid license or key, select Troubleshoot below. (0x803fa067)

Troubleshooting does not help here. It just points me to the Microsoft Store.

I have verified an MSDN developer key would work, so activation itself isn't the issue, but the lack of a key in BIOS/UEFI appears to be the problem.

Thoughts?

In the end, we found that machines that had motherboard servicing were not set up with an OEM key in BIOS/UEFI.

The cards with keys Dell sent were all bad, most likely MS invalidated them. MS confirmed they were bad.

Dell noted that any machines under warranty they would fix, but the rest are not fixable under warranty, and we are reimaging with Linux or a BYOL license.

Here is a helpful command to find if an OEM key is in BIOS/UEFI.

wmic path softwarelicensingservice get OA3xOriginalProductKey

If that returns empty, there is no Dell OEM key, and Windows won't activate.

If there is, it will. We are now auditing our fleet before end-of-warranty.