About this manual
This manual contains service and reference information for the following ThinkPad
®
product:
ThinkPad L390 Yoga Machine types: 20NT, 20NU
ThinkPad L390
Machine types: 20NR, 20NS
ThinkPad S2 Yoga 4th Gen
Machine type: 20NW
ThinkPad S2 4th Gen Machine type: 20NV
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.
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