420 Series
4-3
Before You Begin
Look over the procedures in this section before you begin disassembling the computer.
Familiarize yourself with the disassembly and reassembly steps. Begin each procedure by
removing the AC adapter and the battery pack as instructed in section 4.2, Battery Pack.
1.
Do not disassemble the computer unless it is operating abnormally.
2.
Use only the correct and approved tools.
3.
Make sure the working environment is free from the following elements whether
you are using or storing the computer:
❑
Dust and contaminates
❑
Static electricity
❑
Extreme heat, cold, and humidity
4.
Make sure the FRU you are replacing is causing the abnormal operation by
performing the necessary diagnostics tests described in this manual.
5.
Do not perform any operations that are not necessary and use only the described
procedures for disassembling and installing FRUs in the computer.
6.
After removing parts from the computer, place them in a safe place away from the
computer so they will not be damaged and will not interfere with your work.
7.
You will remove and replace many screws when you disassemble the computer.
When you remove screws, make sure they are placed in a safe place and are
identified with the correct parts.
8.
When assembling the computer make sure you use the correct screws to secure the
various pieces in place. Screw sizes are listed in the corresponding figures.
9.
The computer contains many sharp edges and corners, so be careful not to injure
yourself.
10.
After you have replaced an FRU, make sure the computer is functioning properly
by performing the appropriate test on the FRU you have fixed or replaced.
