About this manual This manual contains service and reference information for the following ThinkPad® products. ThinkPad T480 Machine Type (MT) 20L5 and 20L6 Use this manual along with the advanced diagnostic tests to troubleshoot problems. Important: This manual is intended only for trained service technicians who are familiar with ThinkPad products. Use this manual along with the advanced diagnostic tests to troubleshoot problems effectively. Before servicing a ThinkPad product, be sure to read all the information under Chapter 1 “Safety information” on page 1 and Chapter 2 “Important service information” on page 21. © Copyright Lenovo 2018 iii