CRACKED PIN BLOCK!

This is the most elusive henchman of Basket Cases.  As mentioned earlier, pin blocks are rarely visible.  There is actually no piano that has ever been made where the complete pin block IS visible.

This picture shows a glimpse of the pin block's top view.  It is visible because we tore the factory-glued felt away from the pin block to catch a look at it.  There's a sure way to be removed from a home or showroom!  This confirmed our suspicion why certain tuning pins were much looser than others.  The pin block is riddled with these cracks.  While this one only went through one of the block's laminations, it is suspected that others which could not be viewed penetrated several or all laminations.

This represents a complete fatality.  The piano will never hold a tune again.  Pin block replacement is really only an option in grand pianos, since the eventual resale value of a grand will likely allow for a multi-thousand dollar repair (like a replaced pin block).  Money Pit Example #4.

There is only one atrocity worse than a cracked pin block, and that's a cracked plate.  When there's a crack in the plate, you also have a potentially dangerous situation if it is in a strut.  Pianos with cracked plates can actually explode.  This is EXTREMELY RARE, but it can happen and has happened. Click the link above for a picture. 

With up to 60,000 lbs. of pressure being stretched across its cast iron plate, a crack in the strut of an iron plate significantly weakens the frame.  That pressure wants to go somewhere.  After all, it's the pressure that caused the crack in the first place.  A piano with a cracked plate should immediately have the string tension released and should be permanently relieved of its duties.  It poses no danger as long as there is no tension on the strings.