The red and green diodes are not visible outside the amp. They are only visible inside the amp when the bottom cover is removed. When the amp is built and you turn the amp ON the red diode should light which just shows the proper application of power to the board. The green diode will light only after the relay clicks on and high voltage is applied about 17 seconds later.
These two diodes are only indicators for the builder of the board. I had a situation a couple of weeks ago where a kit builder Emailed me and mentioned that the red diode came on but the green diode never came on the relay never clicked. I had him remove the board and examine the underside of the board where the solder connections are made. Sure enough, he had forgotten to solder one of the six connections of the relay to the TDR board. Upon soldering that connection, the board worked fine ...
From outside the amp though you can hear the relay "click" when high voltage is applied.