Repairs
I used to be a top shelf warranty station for a number of large manufacturers. Working on mass produced instruments is a great way to gain a superiority complex regarding proper building techniques. By the same token, working on high quality instruments built by artisans who take great pride in their work (like Smith, MTD, F Bass, Sadowsky etc.) is a great way to remain humble.
About two years ago, I chose not to renew any large manufacturer certs because I grew sick and tired of picking up the ball for the considerable shortcomings of the amatuer cookie cutter instruments which saturate the market. I don't do warranty work anymore. All the same, if you're local to Philadelphia and have an instrument that requires anything from a broken headstock to a loose wire you're welcome to make an appointment and bring it in.