Having your gear worked on can be a tricky matter, and something like finding the right doctor you can trust. In my experience this has certainly also went for car mechanics, too! Your guitar is a highly prized and special, delicate thing, that truly only you honestly know. Sometimes it can fall in the hands of a repair shop that is a little too “curious”, and they may start to bother with and fool around with your guitar, doing things they weren’t even asked originally to do!
This just happened to me, as I brought two of my prized instruments to a heretofore, unknown shop that was recommended to me by a close friend. The guitars were ONLY brought in for “grind and polish” jobs of their frets, and there was not a single electronic issue needed. Well today I get a call that one of the guitars, a three-pickup model, suddenly has 2 pickups not working at all! Now, how can this happen…? I was literally recording with it, using all combinations of pickups, just hours before it was brought to the shop, and all it needed was for the frets to be polished. Yet, I get a call from the guy who’s shop it is, saying the two pickups are not working! My first reaction, is of course, total rage, as I feel that this guy must’ve started fiddling around inside the guitar to see what made it tick, and somehow broke a wire or two! I always handle my guitars very carefully, and this model, a custom signature model bearing my name, has never given me a second of trouble in the 10-plus years I’ve owned it. Something must’ve happened….
There’s always something a little traumatic about bringing your guitar to a shop for repairs, because you never really know what will be uncovered. When I was just 15, I can still recall seeing my ’52 Les Paul totally taken apart in Dan Armstrong’s shop in NYC by Bill Lawrence. That was surely a shock, because I’d never seen an electric guitar stripped naked of its mechanical and electrical parts before, let alone my cherished Les Paul, which at the time was my only guitar! To see it like that was a scary proposition, but certainly a learning experience, to say the least!
I just know that even though I have 2 or 3 truly trusted luthiers I can feel okay with handling my guitars, it never fails that there is a time they look inside of the guitar, and say something like “what the heck did that guy do to it?! It’s so much like car mechanics, too…always noticing, (truthfully or not) that something unsavory had been done to the instrument or car, before it came to them! Sometimes I think these people do it to cover themselves in case something bad happens later, or it’s already a cover-up for something that’s gone wrong, but they won’t tell me about!
Either way, the fate of my beloved guitar is still in question, but all I can say to you is to be careful just who you let work on your instrument! And I’d especially be wary of when they start to criticize somebody’s “previous” work on the guitar! Make sure they show you, ad demonstrate to you, exactly what they mean! Good luck!