mac Serial number missing - Need Help

[P24601]

Hi guys 

I have managed several mac PRO.

but there are curios thing about mac's serial number.

some mac doesnt have serial number and its inconsistent.

sometimes its 3 or 4

pls anyone tell me why or suspected

thank you

[PaulHazelden]

Have the Macs been away for repair? Sometimes during the repair process the serial number can be lost. It can also be lost if the Motherboard is swapped. The repair people have access to a utility where they can put it back on the Mac.

[P24601]

Yes I checked those MACs are repaired or had forensic problems.

but i cant understand missing macs status are unstable.Its keep changing in a day.

thanks for help.

[jcarr · Accepted solution]

If these devices were serviced by an Authorized Apple Service Provider, there is a process to ensure the replacement logic board has the correct device serial number.  It's possible that this process was not completed correctly.  You may want to check with your service provider.

As for the device record changing, you may want to check to make sure that you are looking at the same device record (check the record ID in the URL).  When a device has a logic board replacement, it will have a new UDID even if it has the same serial number, and will then create a new record in Jamf Pro when enrolled.

[pbenware1]

Many years ago (decades) I worked for a gray market reseller of refurbed Mac parts, including logic boards.  Missing or invalid serial numbers were a common issue, although at the time the impact was very low.  Today, Apple Authorized repair centers and Self Service Providers (like the Higher Ed I work for now) have the tools, and are required, to add the serial number to replacement logic boards.  Its part of the repair process.