Originally Posted by Lennyuk
efs doesn't wipe by itself, if you have IMEI nul that means efs has been corrupted or deleted which is usually due to you doing a mod incorrectly. None of the current root methods will touch efs.
So as I though and I wrote before. Root is not failure for IMEI Null. So, he should just flash kdz to stock and turn it back. In that way he could say it happen by itself, thats it. No paying for new motherboard.