Why Doesn't the Upright Piano Hammer Strike the Strings? The stick key F(4).

[maxim_tuner]

https://youtu.be/Eb7hEnI9Bmo

• Possible Solutions to the Issue of the Hammer Not Striking the Strings:
  
  1 Broken 'the Jack Flange of the wippen: Replace or repair the damaged flange.
  2 Loose or Missing Jack Screw/Pin: Reinsert or tighten the screw/pin that secures the jack to the wippen.
  3 Detached Jack Flange: Remove the action, unscrew 'the wippen', and reattach the jack flange using PVA glue.
  4 Malfunctioning 'the Jack Spring': Adjust the tension of the jack spring or replace it if damaged or lost.
  5 Hammer Rubbing Against Neighbor:
  Loose Hammer: Secure the hammer using a screwdriver.
  Misaligned Hammer: Adjust the hammer position to ensure it strikes all three strings evenly.
  Stuck Hammer: Use a screwdriver to spread the flanges of the problematic hammers.
  Additional Notes:
  
  When inspecting the hammer, ensure that the striking surface of the hammer head makes contact with all three strings (chords).
  If the hammer is loose in its seating, use a regular screwdriver to tighten the screw.
  For additional lighting, use a flashlight or lamp.
  When spreading the flanges of stuck hammers, use a long screwdriver with a thin tip.