On a Dell Latitude 7420, the laptop computer has a power button on the right corner of the computer. If the power button is stuck, it may have to be replaced. The power button is located underneath the motherboard, and the button is held down by two screws.
To start, remove the back plate located underneath the laptop. Once this is removed, the internal system components will be exposed such as the motherboard, ram, battery, etc.
Next, remove the battery cable. It is unnecessary to remove the entire battery from the system because the battery sits in an area where there is enough clearance to remove the power button.
Remove the all of the connectors connecting to the motherboard. All of the connectors are circled in white. On the far right are two screws holding down a separate circuit board that is connected to the motherboard.
After the connectors are disconnected, remove the screws holding down the motherboard. For this model, there is a separate board connected to the main board. This secondary board holds a USB – C port connection and is located on the right side of the picture. This port also has two screws holding it down. All of the screw locations are circled in white.
There is also a screw located on the lower far left of the picture.
After all of the connectors and screws are removed, the motherboard can be removed. It is unnecessary to disconnect the motherboard from the secondary board. The secondary board is the board that houses the USB-C. The motherboard and secondary board can be removed as one piece. A pry tool may help to remove the secondary board along with the main board together. In addition, the heat sink and fan can also be removed together with the motherboard as one piece. There are two screws holding down the fan, so once these two screws are removed the fan should be able to be removed along with the other components.
The power button should be revealed once the components such as the motherboard, heat sink, and fan are removed.
The power button is a separate unit in this system.
