Note: In models with the fingerprint reader, the sensor is attached to the palm rest FRU. If the fingerprint reader has any defects, you can replace it by the procedures given in this section, which are the same for a palm rest with or without a fingerprint reader.
Please perform the following steps as shown in the pictures below.
Palm rest or palm rest with fingerprint reader installation
When installing: When you attach the palm rest, do as follows:
Attach the color sensor connector  and the fingerprint reader connector  firmly to the system board. Some models have only the fingerprint reader connector.
Attach the palm rest as shown in this figure.
Push the front side of the palm rest  and the areas marked  until it clicks into place.
Close the LCD cover and turn the computer over. Then fasten the four screws to secure the palm rest.