Martin Logan Odyssey power supply board testing

I have a pair of Odysseys that I bought in 2005 and replaced a power supply in one of them about ten years ago. Here we go again.....I think. First, does the blue lighted ML badge behind the transducer panel light only if there is an audio signal applied like on some DAC's, or should It always on when plugged into house power. Second, which board is the power supply, the small one at the terminals or the large board on the woofer wall? The third question is where do I measure bias voltage to determine if it is, in fact, not producing ht voltage and, what should that voltage be.

I know that the best authority should be, and they are always very helpful, Martin Logan themselves but, in the end I would like to make this into a DIY project and try troubleshooting toward the goal of replacing an inexpensive component instead of replacing another circuit board at a cost of $380.