Dell P/N: 0YF81X. Used, genuine and fully working part.
Dell Inspiron 3521, Latitude 3540 Laptop Power Button Board & Cable LS-9101P
Dell Inspiron 3521, Latitude 3540 Laptop Power Socket / DC Jack & Cable. 0YF81X
Dell Inspiron 3521, Dell Latitude 3540 Laptop Mouse Buttons Board. P/N: LS-9103P
Dell Inspiron 3521 3537 5521 5537 Latitude 3540 UK Keyboard - 1 Key + Hinges +
Dell Inspiron 3521 USB I/O Circuit Board with Ribbon Cable - 075PM1 75PM1
DELL INSPIRON 3521 3531 USB BOARD & CABLE LS-9102P 075PM1