removal of the trigger assembly is quite simple, there are two platic hooks (one at top of mobo, one near bottom of mobo, at bottom of trigger, and three solder points. un hook the bottom hook, use a solder sucker to remove the solder at the three trigger points, and use your iron to push the three pins done through the mobo.
all the action of the trigger is handled by those three points, it sounds like the top and middle pin are bridged.
top pin is vdd bottom is gnd, and the center is the wiper