Lenovo 20RK, Hardware Maintenance Manual

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Chapter 7. Removing or replacing a FRU
This chapter provides instructions on how to remove or replace a FRU.
CRU statement for customers :
You can resolve some problems with your product 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. For optional-
service CRUs, you can either install the CRU yourself or you can request that a Service Provider install the
CRU according to the warranty service for your product.
If you intend on 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 can find a list of CRUs for your product in this
Hardware
Maintenance Manual . An electronic version of this manual is available for downloading at https://
support.lenovo.com . You might be required to return the defective 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
might 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.
General guidelines
When removing or replacing a FRU, be sure to observe the following general guidelines:
1. Do not try to service any computer unless you have been trained and certified. An untrained person runs
the risk of damaging parts.
2. Before replacing any FRU, review Chapter 6 “FRU replacement notices” on page 39.
3. Begin by removing any FRUs that have to be removed before replacing the failing FRU. Any such FRUs
are listed at the beginning of in each FRU replacement section. Remove them in the order in which they
are listed.
4. Follow the correct sequence in the steps for removing a FRU, as given in the drawings by the numbers in
square callouts.
5. When turning a screw, turn it in the direction as given by the arrow in the drawing.
6. When removing a FRU, remove it in the direction as given by the arrow in the drawing.
7. To put the new FRU in place, reverse the removal procedure and follow any notes that pertain to
replacement.
8. When replacing a FRU, use the correct screws as shown in the replacement procedures.
DANGER
Before removing any FRU, turn off the computer, unplug all power cords from electrical outlets, and
then disconnect any interconnecting cables.
Attention: After replacing a FRU, do not turn on the computer until you have made sure that all screws,
springs, and other small parts are in place and none are loose inside the computer. Verify this by shaking the
computer gently and listening for rattling sounds. Metallic parts or metal flakes can cause electrical short
circuits.
Attention: The system board is sensitive to, and can be damaged by, electrostatic discharge(ESD). Before
touching it, establish personal grounding by touching a ground point with one hand or by using an ESD strap.
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