Why is the black key (F#) stuck on the upright piano and how to fix it DIY.

[maxim_tuner]

https://youtu.be/yqBH4F-2RxY?si=Yj0JHvIxdFqthDIY

• 'The front rail key pin' (F#) is not properly aligned. Each 'the front rail key pin' has a thread that allows it to be regulated. Sometimes, during the production of the upright piano, the top of 'the front rail key pin' is not centered in the specified position relative to the key's hole cloth bush. Alternatively, 'the front rail key pin' itself may have shifted. As a result, when a key is pressed, 'the front rail key pin' lightly gets wedged against the cloth edge of the key's hole bush. This can be visually observed in the video, as there is some friction between 'the front rail key pin' and the hole of the key bush.
  
  Here's how to fix it:
  
  1 Open the topmost cover of your upright piano (top board) or (front cover).
  2 Remove the upper front board, which is fixed in place with two spiners.
  3 Lift up the keyboard cover (fallboard).
  4 Unscrew and remove the wooden top stick that is located above the keyboard.
  5 Remove the keys (F#), as well as the neighboring (F) and (G) keys for easier access.
  6 Using pliers, carefully rotate 'the front rail key pin' (F#) so that its top edge aligns parallel to the key's outlet.
  7 Reinstall the key (F#) and test it. Also, reinstall the neighboring keys.
  8 Make sure that the key (F#) moves smoothly and does not get stuck.
  9 Reinstall all the keys and ensure that there are no wedges or obstructions between them.
  If all of the steps are followed correctly, the key should no longer be stuck.
  Note: Proceed with caution if attempting to fix it yourself.