Take your secondary apart. Face it down with the helix facing upwards. If you can't push the helix down try giving it a solid smack with a rubber mallet. Hold it down and with some snap-ring pliers take the c-clip off. Be sure to hold onto the helix so you can look in and see which holes the spring is in.. Your spring could be weak and not giving you the back shift or the bushings where the helix rides could be worn out. If you can see silver through the gold of the bushing it is time to replace. Same goes for the little one on the front. Clean it check the buttons and try it from there. Remember to give the helix a quarter turn when you put it back in. It needs to be pretentioned.