X390 Motherboard NM-B892 5B21C98905 5B21C98908 5B21C98899 5B21C98900 For Thinkpad X390 20SC 20SD i7-10710U 16G/8G 100%Test OK - AliExpress
Amazon.com: Genuine Parts for Lenovo ThinkPad x390 20Q0 20Q1 13.3 inch i7-8565U(1.9Ghz) 16GB HD UMA Graphics System Motherboard 5B21C98781 : Electronics
Lenovo ThinkPad X390 Core i5-8365U 1.60 GHz 8 GB DDR4 Motherboard 5B21C15301 at TR Reuse Group