Lenovo T420i manual FRU replacement notices, Screw notices, External CRU statement to customers

Chapter 7. FRU replacement notices

This chapter presents notices related to removing and replacing parts. Read this chapter carefully before replacing any FRU.

External CRU statement to customers:

Some problems with your product can be resolved with a replacement part you can install yourself, called a “Customer Replaceable Unit” or “CRU.” Some CRUs are designated as Self-service CRUs and others are designated as Optional-service CRUs. Installation of Self-service CRUs is your responsibility; you may request that Lenovo installs an Optional-service CRU according to the warranty service for your product. Where you are installing the CRU, Lenovo will ship the CRU to you. CRU information and replacement instructions are shipped with your product and are available from Lenovo at any time upon request. You may find a list of CRUs in the publications that ship with your product or at http://www.lenovo.com/CRUs. You may be required to return the defective part that is replaced by the CRU. When return is required: (1) return instructions, a prepaid shipping label, and a container will be included with the replacement CRU; and (2) you may be charged for the replacement CRU if Lenovo does not receive the defective part within thirty (30) days of your receipt of the replacement CRU. See your Lenovo Limited Warranty documentation for full details.

Screw notices

Loose screws can cause a reliability problem. In the ThinkPad Notebook, this problem is addressed with special nylon-coated screws that have the following characteristics:

•They maintain tight connections.

•They do not easily come loose, even with shock or vibration.

•They are harder to tighten.

•Each one should be used only once.

Do the following when you service this machine:

•Keep the screw kit (for the P/N, see “Miscellaneous parts” on page 156) in your tool bag.

•Always use new screws.

•Use a torque screwdriver if you have one.

Tighten screws as follows:

•Plastic to plastic

Turn an additional 90 degrees after the screw head touches the surface of the plastic part:

•Logic card to plastic

Turn an additional 180 degrees after the screw head touches the surface of the logic card:

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