Hello everyone.
First, I should mention that I have a used Yamaha U1 upright piano, purchased 2 years ago for my daughter who is taking private lessons. I have also approached the instrument by trying to play for pleasure, having a long-standing youthful passion as a guitarist.
About a year ago, while trying to play pianissimo, I noticed that key 59 (G5) does not emit any sound if pressed with the same light pressure exerted on adjacent keys; trying to analyze the reason, I press the key very slowly to see if I can perceive the cause. I notice that at about 50% of the total travel, the key becomes harder and then makes a click as it descends all the way down.
So, I remove the protection to look at the action and I see that the escapement lever does not escape with the same ease as the other keys exactly at the moment when the key becomes harder.
Shortly thereafter, on the occasion of tuning, I call the "technician" who sold me the piano and point out this problem to him. He tells me it is a regulation issue and after adjusting the eyelet screw of the escapement button, he tells me that it is now resolved (according to him) and that the piano just needed to be played more often and everything would be fine. In reality, yes! It had improved, but I still felt that slight click.
One month ago, as if by chance, while playing pianissimo, key 52 (C5) becomes completely stuck; it goes down 1mm and no further, I do not press harder sensing that something has gone out of place. I re-watch your magnificent tutorial on the action and decide to carefully examine all the components of the mechanism following their function. I discover that the string attached to the repetition lever fork is torn and the spring has lifted and hits directly against the damper blade located right in front of it. Returning it toward its normal position, the key unblocks and descends, but unfortunately when playing, the spring—no longer held by the string—lifts up again and we are back to square one. So, I slightly bend the spring so that it fits exactly between one damper blade and the adjacent one. I then go back to check the first key, 59, which had the click. Same reason: the string is torn and the spring brushes against the damper blade, creating enough friction to cause that click.
Worried, I analyze all the keys. Another 9 have torn strings, but in these latter ones, more fortunately, the spring has slipped between one blade and another. I attach a couple of photos of the torn strings.
Now I am playing in these conditions where the hammer returns less quickly and with some extra oscillation before stabilizing. But my low level as a "piano plunker" (I don't dare call myself a pianist, I wouldn't want to offend anyone!) doesn't make me notice any problem. But I believe that a pianist, in the true sense of the word, would notice it, and furthermore, I am bothered by the thought of those little springs lying there at the mercy of the keys, and it seems to me I can hear them imploring: "we only ask to be able to do our duty!".
After this endless chronicle, I come to the question. Should I assume that I will soon have to expect more torn strings? What could be the cause? Age? The piano is from around 1975 (deduced from the serial number). What procedure is necessary to repair them?
thanks for listening to me
Alfredo
