"Mate, the easiest thing is to get a cheap voltmeter and see whats coming out of your power module. This will save you a lot of time - you never know, it might be the power regulator on the APM board - but until you've done what I suggest you're…"

"Good build advice at rcexplorer: http://rcexplorer.se/projects/2011/09/the-tricopter-v2-5/

Excellent APM config + tips here: http://www.rcgroups.com/forums/showthread.php?t=1792924"