I can not tell you why but I don't think the blue LED light on the mana board should be blinking. Something is not right but what it is I don't know. You may want to try to reload the firmware. Unless you know something about the design of the mana board then the easiest guess is to try a new board and see if that work. Maybe there is a power issue or a connection issue with the cable and accessories attached to the board. Ask @EleksMaker under what conditions the Blue LED will blink instead of continuous. Ask also @Zax he has a good understanding about the unit electronics.
I agree, the light should be on and not blinking. In my case just connecting red/black to the laser keeps the light on. As soon as I connect the yellow wire the light dies and then comes back, resulting in a slow, pulsing blink.
This may have a number of reasons, a faulty Mana-board being just one. It may also be an issue with the laser module, that's why I was asking. Measuring output at the cable connection shows the expected voltage, though I do not have an oscilloscope here and therefore cannot check it in more detail.
Since the Mana Board seems not to be available right now from the shop I will try replacing the laser.