I'm worried about my miners...

Occasionally it would show a status of

oooooooo oooooooo oooooooo oooooooo
xxoooooo oooooooo oooooooo oooooooo

When i reboot the antminer, it switches around to

xxoooooo oooooooo oooooooo oooooooo
oooooooo oooooooo oooooooo oooooooo



Should i be concerned about this at all? Could it be the power supply or heat, or is my antminer is just stupid...