Have a look as there are 5 LED's in total in this area (in 2 rows: one is 3-LED, second is 2-LED). 3 of them are CPU Voltage, 2 of them are CPU temp.
If CPU temp is below some value then all CPU temp LED's should be off, check details in manual.
I wouldn't worry at all about them, it's something which is just nice to have a look at (if you have opened chassis or one with with transparent window).