This Yashica-A TLR has 'issues' with the shutter firing mechanism
making correct contact to release the cocked spring, thus allowing
the shutter blades to open and close.

Nothing that a hammer cannot fix. ;-)

PS. Ignore the loss of the vulcanite (yes, not leatherette on the 'A')
- it is 'petrified' and cracked in several places and is to be replaced.