AVA Vision Hybrid DAC flashing power switch

[vonclod]

I can't find my manual, and none seem's to be available ol, I know a member here works for AVA.
What I noticed tonight is the lighted power switch was flashing..I'm not sure what that means,,the dac was working ok, but I was just using it for the tv/cable box at the time(not critical listening)
Any idea's? time for new tubes maybe?

Thanks