Why Doesn't the Upright Piano Hammer (G4) Strike the Strings? How to Fix It Your

[maxim_tuner]

In this video, it appears that the upright piano's "jack of the wippen" is not striking the "hammer butt" fast enough, and its "back check" is catching the "hammer butt." This issue requires an adjustment to increase the "letoff" distance.
How to Fix It:
1 Utilize a screwdriver for this task. Insert the tip of the screwdriver into the hook of the "let off regulation" screw.
2 Gently turn the screw of "the let off" clockwise by half a turn or more, as needed. The aim is for the upright piano's "jack of the wippen" to firmly reach the "let off button punching" when the upright key is pressed. In other words, we are attempting to bring them closer together by adjusting (screwing in) the "let off" within the "letoff rail" (the wooden retaining plank). https://youtu.be/2vqkfQTVQeM
It's possible that do in other cause too:
1'The jack flange' is broken.
2 The pin/screw securing 'the jack to the wippen' has come loose or fallen out.
3 'The jack flange' has detached from 'the wippen'.
4 'The jack spring' has come loose, is damaged, or lost. The spring should push the jack forward. How to Fix It: 1 If the pin/screw securing 'the jack to the wippen' has come loose or fallen out, you can attempt to reinsert the pin into 'the jack flange's hole' using a screwdriver.
2 If 'the jack spring' has come loose, is damaged, or lost, gently pull the spring upwards to increase its tension. If it's damaged, replace it with a new one.
3 If 'the jack flange' has detached from 'the wippen', you'll need to remove the action from the piano and unscrew 'the wippen' from the action. Then, use PVA glue to reattach 'the jack flange' into the groove of 'the wippen'.
4 You have the option to either glue the broken flange or replace it with a new one.