I put three newly built modules and one second-hand in my new chassis that has never been used before. They all had tested fine (only put on ps one at a time) and everything was in the right place. When I went to test if they would pass signal there was kind of a galloping/heartbeat sound and the power LED was dimming in rythm to this pulsation. I turned it off and disconnected all the output cables.
I turned it on and it was not pulsating anymore so I went to connect one output cable at a time to see which module was causing trouble. The cables were connected to the trs inputs of my m-audio profire 2626.
When I got the first cable near the T15 module a huge spark arced from the cable to the vicinity of the jack, not sure if pins or chassis but now the PS will not power on at all.
The fuse did not blow and there is nothing visibly hot/damaged looking. I'm measuring wall voltage going into one side of L4 but figured I'd better ask before I do anything else.