wireless internet -
when it is working: the cable box lights - power, cable, pc lights are on constantly while the data and test lights and blinking. The airport express - center light is on constantly, the two side lights are blinking.
when it wasn't working (8/24/08) - on the airport express, the left light is off (take airport off wall and look at it straight on; it is the right light as it is mounted on the wall).

Onkyo sound system -
test whether sound is coming out of the left, right and center speakers. 8/24/08 - I pushed "surround" button and chose PL II, then was able to get sound. This was using FM as test sound source.