thought I'd save other newbies this problem.
Plugged in a wall wart, 12 volts, center pos. No joy. no lights. Measured the power on the connector and it was ~15v.
Tried a bench power supply at 12 v and the lights came up and the Joule booted.
BEWARE THE WALL WART WITH ITS LOOSE SPEC!
Someone asked about the draw and my board at idle seems to be consuming 0.2 amps