A1398 EMC 2881 Odd Dump

Hello,

I have an A1398 from 2014 (EMC 2881, Core i7) that indicates "Unavailable" for its serial number and is thus unable to sign into iMessage and having other iCloud-related authentication problems.  I used cmizapper with a ch341 to retrieve an EFI dump and had to inject 3.3v from a DC Power Supply per the instructions for that device.  I've used the ch341 in the past with success, but haven't had to inject 3.3v directly to the board yet.  If I didn't inject the voltage, flashrom reported No EEPROM/Chip found.

I was able to retrieve three dumps of the EFI and the sha1sums matched each other, so I thought it would be straightforward after that.  Usually if there was a problem with
voltages or the read, the sha1sums would not match.  However, in opening the file I don't see many familiar strings from other EFI dumps, notably looking for anything related to the serial like 'hwc' or similar.  The dump does contain $SVS twice but the computer is not
passcode locked. 

Would someone be able to take a look at the attached and let me know if I should attempt to fix this, attempt to re-read it, or simply write an EFI with a clean ME from elsewhere?