User Guide

4.18 Heat sink/CPU 4 Replacement Procedures
Installing the Heat sink/CPU
The following describes the procedure for installing the heat sink/CPU. (See Figure 4-32 to
4-34.)
1. Make sure that the cam of the CPU socket is in the unlock (OPEN) position.
2. Install the CPU on the CPU socket and check the CPU is installed on the correct
position.
3. Lock the CPU by rotating clockwise the cam on the CPU socket by 90 degrees with a
flat-blade driver.
4. If there is already silicon grease on the CPU and heat sink, clean it with a cloth.
Using a special applicator, apply silicon grease so that the CPU chip on the CPU is
completely covered.
NOTE: Apply the silicon grease enough to cover the chip surface using the
special applicator.
Figure 4-34 Applying silicon grease
5. Install the heat sink on the CPU.
6. Install the CPU hold plate and secure it with the following screws in the order of the
number on the CPU hold plate.
• M2.0×4.0B BIND screw ×3
CAUTION: Tighten the screws in the order of mark “1”, “2” and “3” on the CPU
holder.
PORTEGE M400 Maintenance Manual (960-541) [CONFIDENTIAL] 4-53