HP TC4400 - Manual (Page 109)

5–26 Maintenance and Service Guide
Removal and Replacement Procedures
6. Lift the right side of the heat sink 1 to disengage it from the
processor.
7. Slide the heat sink up and to the right 2 to remove it.
✎
Due to the adhesive quality of the thermal paste located
between the heat sink and processor, it may be necessary to
move the heat sink from side to side to detach the heat sink
from the processor.
Removing the Heat Sink