Help!!!!! Late 2013 rMBP and Blank Board Serializer Issues

Hi all! I just replaced the logic board in my cousin's late 2013 13" Retina MacBook Pro (2.4 GHz, 16 GB, 256 GB). When I booted it up, the serial number now displays as "Unavailable" in About this Mac. I've tried using two different versions of Blank Board Serializer to set the serial number to the one on the case. With one version, it boots successfully and I can go through all of the prompts, but at the last second it craps out and gives me "error 460". With the other version, it can be chosen from the boot selector, but it gives me an EFI error and a cursor. How can I resolve this? The nearest Apple Store is several hours away and they aren't very friendly with home repairs.
Thank you so much!
David

PS- This is my first post, so I apologize if I don't have good forum etiquette.

Welcome to our forums.

You're going to need to take the machine to Apple in order to "burn" the new serial number into the firmware. I'm not sure those apps you cited still work. I don't know of another method of doing it. Normally, when Apple swaps out a logic board they take care of matching the serial number with the one on the new or refurbished board.

Either that, or don't worry about the serial number being displayed. If the machine is no longer under Apple Warranty, there should be no problem. You can document the new serial number so that if your cousin ever decides to sell the machine he/she will have that to verify.

Thanks for the response! Normally I wouldn't worry about it simply not being displayed, but without a serial number I can't use iMessage or iCloud, but more importantly I can't even install macOS because the installer can't verify the computer with Apple. I still have some hope that it can be done, if nothing else than because I've heard of newer machines being successfully re-burned. Thanks!

OK, that makes sense. I hadn't thought about installing macOS. You're correct. Let us know if you come upon something that works. Good luck.