When handling the system board, bear the following in mind.

• The system board has an accelerometer, which can be broken if several thousands of G-forces are applied.
  Note: Dropping a system board from a height of as little as 6 inches so that it falls flat on a hard bench can subject the accelerometer to as much as 6,000 G's of shock.
• Be careful not to drop the system board on a bench top that has a hard surface, such as metal, wood, or composite.
• If a system board is dropped, you must test it, using PC-Doctor for DOS, to make sure that the HDD Active Protection System™ still functions.
  Note: If the test shows that the HDD Active Protection System is not functioning, be sure to document the drop in a reject report, and replace the system board.
• Avoid rough handling of any kind.
• At every point in the process, be sure not to drop or stack the system board.
• If you put a system board down, be sure to put it only on a padded surface such as an ESD mat or a corrugated conductive surface. After replacing the system board, run PC-Doctor for DOS to make sure that the HDD Active Protection System still functions. The procedure is as follows:
  
  1. Place the computer on a horizontal surface.
  2. Run Diagnostics --> ThinkPad Devices --> HDD Active Protection Test.
     
     Attention: Do not apply physical shock to the computer while the test is running

   

For access, remove these FRUs in order:

• Battery pack
• Hard disk drive door
• Hard disk drive or solid state drive assembly
• PCI Express Mini Card for wireless LAN
• PCI Express Mini Card for wireless WAN
• Backup battery
• Keyboard
• Keyboard bezel assembly and power button board
• Bluetooth daughter card

Note:
Loosen the screws [1] in order as shown in the following figures.

When installing:

• Before you attach the fan assembly to the computer, clean out residual thermal interface material on chips, because residual thermal interface material can cause a thermal problem due to imperfect contact with a component.
• Tighten screws [1] in the reverse order that they were removed.

The 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] CPU
[b] Graphics Processing Unit (GPU) (discrete graphics chip)

When installing:
Make sure that the connector is attached firmly.

When installing:

• Make sure that the cables are attached to the cable guides firmly.
• Make sure that you route the cables correctly and you tape up the cables in the proper positions as shown in the following figure.
• When you route the cables, make sure that they are not subjected to any tension. Tension could cause the cables to be damaged by the cable guides, or a wire to be broken.

The new base cover FRU is shipped with a kit containing labels of several kinds.
The following figure shows the location of each label.

Note:
If the Windows Certificate of Authentication label (COA) 1 is attached to a part that is replaced, return the old part with the label attached to the customer, or provide a letter to the customer stating what the label was originally on the system and what the label part number, serial number, and product key were.

When you replace the base cover, apply the following labels:

[2] FCC label
[3] Homologation label
[24] Battery word label

The following labels need to be peeled off from the old base cover, and need to be put on the new base cover.

[1] Windows Certificate of Authentication label (COA)
[4] China Mobile label
[5] Qualcomm FOX Gobi 2000 label
[6] System label
[7] China Telecom label
[8] Certified label
[9] S/N barcode label
[10] Wireless LAN label 11 Mac address label
[12] SIM card label
[13] Rating label (Indonesia)
[14] Non Encryption label
[15] Israel label
[16] Postel label by SKU (Indonesia)
[17] SIRIM label
[18] Brazil Anatel BT label
[19] Brazil Anatel BG label
[20] Brazil Anatel WWAN label
[21] Asset tag 22 SIM ICCID label
[23] China WWAN label

For some models, you need to apply two FCC labels. Check the old base cover; if it has two FCC labels, apply both to the new base cover.