Donβt know why my DS918+ is sick that Disk 1 LED indicator is away with orange color. After checking with Synology technical support, it is confirmed that Disk1 connector is with some issue. As still under warranty, I triggered aRMA process through local retailer before CNY.
After 3 weeks away, my DS918+ disk station come back finally. 
Synology just replaced a new set. Thanks for the satisfied support from local retailer and Synology.
