Before inserting the Micro SD card board into the RPi, you need to connect it to the button board using the FFC cable.
Then plug in all cables and secure the RPi with M2.5x4 screws.
Fix the fan with M2.5x9 screws and the side with the logo facing the fan hole.
Finally close the back cover and screw in the M2.5x4 screws.
Detailed Assembly Steps
Take out the RasPad, then flip it over and remove the back cover.
Here is the internal structure of the RasPad. Avoid pressing these two speakers in case of any damage.
Connect the Ethernet port of the Raspberry Pi and the Main Board.
Connect the RPi USB3.0 port and the Main Board via the USB cable.
Plug in 2 Micro HDMI cables.
Plug in the Type-C cable.
Plug the FFC cable in Micro SD card board.
Insert the Micro SD card board into the card slot of the RPi.
Insert the other side of FFC cable into the button board.
Fix the Raspberry Pi with 4 M2.5x4 screws.
Stick heat sinks on the right positions and accordingly insert the Accel SHIM module for the use of auto-rotate function.
If you want to use the I/O pins of the RPi, you can connect a common 40 pin ribbon cable.
Install the fan on the back cover and screw it in with 4 M2.5x9 screws.
The logo side is against the bottom.
Connect the fan to the main board.
Enclose these complete parts with a back cover then screw to get them tightened.
If the enclosure is hard to cover, don’t cure this slight hiccup with violence. Please check these parts out to try to cover again.