If this dead minnow is happening in the summer, it's usually a sign your minnow is below the thermocline with little to no oxygenated water, i.e. fishing to deep. I also bank fish right now as I am rebuilding a boat I purchased, and fish with a bobber/ float to keep the minnow in the strike zone for a longer period of time. I also found that by using a longer jig pole, I can lob the minnow and float farther with less effort and thus not rip the hook from the minnow or make them hit the water to hard thus killing from impact with the water.
I also will try different methods to see what the fish want, be it minnow on a hook, minnow on a dressed jig, or minnow on a plain jig. I have caught different species on all three methods.