After the removal of the cover, we will be able to see the four plastic trays, each which have the Synology logo printed in the middle:
The bays have some small dots printed on the top which represent the initialization order during boot-up:
The product code name can be also found on the bottom left side:
On the right side we will find one Status LED along with four Disk activity LEDs:
Further down we have one USB port along with the Power button with LED:
After removing all the plastic trays, we will be able to see the daughterboard with the SATA Data/Power ports for each bay:
This NAS features the updated trays design which means screw-less installation for the 3.5’’ drives:
The lateral plastic covers are easy removable for revealing the anti-vibration rubber grommets:
To install the drive, we only have to remove the two lateral covers, insert the drive inside the tray and afterwards snap-in the covers back; before re-attaching the covers, make sure that the holes of the drive are aligned with the ones of the tray so the plastic pins of the covers won’t be damaged in the process: