Lenovo ThinkPad T420/T420i User Guide

About this manual

This guide covers everything you need to know about the ThinkPad T420 and T420i, from product overview and hardware locations to operating system installation, ThinkVantage features, and power management. It also includes detailed sections on security, recovery media, and how to replace or upgrade components such as batteries, hard drives, and memory.

Later chapters walk you through advanced configuration, preventive maintenance, troubleshooting common problems, and how to obtain support. Safety warnings and handling instructions are provided throughout to help you avoid damage and injury while using the laptop.

What's inside

• Product Overview
• Using Your Computer
• Security
• Recovery
• Replacing Devices
• Enhancing Your Computer
• Advanced Configuration
• Preventing Problems
• Troubleshooting Computer Problems
• Getting Support

Frequently asked questions

How can I protect myself from heat generated by the AC power adapter?

Do not place the AC power adapter in contact with any part of your body while it is in use.

What should I do if I see signs of overheating, smoke, or sparks?

Stop using the product and unplug it from the power source immediately.