Dell Inspiron 15-5578 Service Manual page 58

Figure 31. Removing the system board cables
1. I/O-board cable
3. keyboard cable
5. system board
7. Remove the screws that secure the system board to the palm rest and keyboard assembly.
8. Lift the system board off the palm rest and keyboard assembly.
a. screws (5)
58 Removing the system board
2. latches (2)
4. speaker cable
6. hard-drive cable