This is taken from the user’s manual at link:
http://www.buffalotech.com/support-and-downloads/documentationThe LS-WXL has 3 front indicator lights - Power, Function and Info/Error. The Info/Error light has 2 colors. Orange is a message while red is an error.
The time and count define the code. A long on time is 1 second. A short on time is 0.5 seconds. The first long light starts the sequence. Your description does not give the right sequence. I assume you have one long on then 6 short on flashes. This will then repeat.
If the light is orange this means your RAID is being created. You’ll need to wait a while for it to complete. Since you have a 3T mirror raid, this maybe 48 hours. Yes, 48 HOURS.
If your light is red, then a 1 long and 6 short means the drive cannot be found. You’ll need to reseat the drive and try again.
There are other codes based on the long on count. You'll need to read the manual or post more details.