I used two s61 MK2 keyboards. The new one has been used for nine months. As the use time is longer and longer, some keys will appear the spring creaking sound, and the key position with creaking sound will also become soft, which makes the hand feel very bad. S61 seems to keep the spring of the piano key through the spring, but the life of this spring seems to be a little short. Is there a friend in this situation, and can this problem slowly return to normal?