Dell Inspiron 15-5578 Service Manual page 54

5. coin-cell battery cable
4. Remove the two screws (M2x3) that secure the I/O board to the palm rest and keyboard assembly.
5. Lift the I/O board off the palm rest and keyboard assembly.
Figure 29. Removing the I/O board
a. screws (2)
b. I/O board
c. palm rest and keyboard assembly
54 Removing the I/O board
6. power and volume-buttons board cable