SteveZ
Active member
Just inside the sound hole is the truss rod adjustment. Here's a link which talks about it.
https://www.mandolincafe.com/forum/threads/65478-Blueridge-40-T-Truss-Rod-Does-yours-have-one
https://www.mandolincafe.com/forum/threads/65478-Blueridge-40-T-Truss-Rod-Does-yours-have-one