I've been having problems with my hi-hat where when I play, the nut holding the top cymbal to the pedal piece becomes loose and starts to fall down to the point where it won't go up unless tightened. I'm not sure if this could be solved by buying another one, or if it would be better to just look into a new hi-hat.
If it makes a difference, I've had my set since I was 14 and it was a cheapo one my dad bought from my friend for me. Its Enforcer by Remo.