Lenovo A2109 Tablet - Manual (Page 29)

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Lenovo IdeaTab A2109A-F
FRU replacement notices
This section presents notices related to removing and replacing parts. Read
this section carefully before replacing any FRU.
Screw notices
Loose screws can cause a reliability problem. In the Lenovo IdeaPad computer,
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 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° after the screw head touches the surface of the
plastic part:
more than 90°
(Cross-section)
Logic card to plastic •
Turn an additional 180° after the screw head touches the surface of the
logic card:
more than 180°
(Cross-section)
Torque driver •
If you have a torque screwdriver , refer to the “Torque” column for each step.
Make sure that you use the correct screws. If you have a torque screwdriver, •
tighten all screws firmly to the torque shown in the table. Never use a
screw that you removed. Use a new one. Make sure that all screws are
tightened firmly.
Ensure torque screwdrivers are calibrated correctly following country
•
specifications.