Light of MyBook Live turns red or white instead of energy-saving-mode (=blue)

What is wrong with this MyBookLive?: is it safe for my data or only a question of time, when it crashes totaly!? 

The light of my MyBookLive turns red or white (instead of blue in energy-saving-mode), when I don’t use it. My second MyBookLive is fine at the same time connected at the same router (AVM FritzBox 7170). 

I changed Cables and Router-Places (Ports? I don’t know the english word: where the cable goes into the router) and still the same: lights of first MyBookLive behave strange.

In the meantime the light on my first MyBookLive bekame weaker and weaker: now it is completly gone (dark).

Both MyBooks are one and a half year old, but the one with the problems has been strange from the start: when I once reset it, I lost it complety and only get a connection to it again with the FAQ-Help. Then I could reset it with success, but later came the problems with the lights.

What is wrong with this MyBookLive?: is it safe for my data or only a question of time, when it crashes totaly!?

Red means drive failure, so I would backup the important files and replace it.