Following components soldered on the top side of the system board are extremely sensitive. When you service the system board, avoid any kind of rough handling.
[a] MCP (Multi Chip Package) processor [b] PCH (Platform Controller Hub) [c] Accelerometer chip for the HDD Active Protection System™ [d] Graphics
Note: [d] (Graphics) is only for the Switchable Graphics models and Workstation models. The system board in Integrated Graphics models does not have this chip.
For Integrated Graphics models:
For Switchable Graphics models:
For Workstation models:
System board assembly and magnesium structure frame installation.
When installing: When you replace the system board, attach thermal rubbers as shown in this figure. Depend on the models you are servicing, the number of thermal rubbers are different. Check the thermal rubbers on the old system board, and find duplicates of them in the new FRU package and apply them to the new system