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Wednesday 14 February 2018 at 21:07
do you have 2 sets of holes for the bottom of the springs, looks kind of close to the base of the target?
the spring is what help's pull the top of the target onto the ledge, that hold up the targets.
Also make sure there's nothing down on the ledge that might not let the targets set.
Source: http://pinside.com/pinball/forum/topic/drop-targets-not-staying-up#post-4230209