I didn't expect this many responses in such a short time. I'll start with the how do you become a mechanic question and answer the others when Richard is around. He started working for a garment factory because in our rural area there really weren't many choices. He worked at the lowest position for a few months and then moved up to something else. After a few more months, the bosses noticed his good work ethic and offered him a position as a mechanic. He had a great boss who mentored him and really taught him the basics. Then the company sent him to different places to learn one machine after another. He wasn't afraid to ask for help and he worked hard to learn everything he could. Eventually his boss retired and they asked him to take over as the supervisor. Then when the maintence supervisor left, he took that position as well, which means he was in charge of fixing the machines and making sure the plant had everything it needed to run: heat, elecrical, water, a/c, air, even controlling the pest problem and getting the grass cut came under his wing. But he really liked it and stayed with it until the plant closed a few years ago. He put the final lock on the door and turned the keys over to the new building owner. Surprisingly, many of the mechanics he knows sort of fell into the position the way he did. On the job trainging and specialized training were the way they all learned the job.
Many home machine mechanics are people who worked in the garment industry and then got certified for a particular brand. Few get certified in every brand because it's a long, expensive process. But unless your machine is under warranty, this shouldn't deter you. The older models are basically the same on the inside. Now if your machine is under warranty, definitely go back to the dealer who sold you the machine so that you don't void the warranty. For example, Richard can fix my new Bernina, but I take it to Baton Rouge to get it serviced. A certified guy must be the one to break the seal. Richard fixes and services my older machines because they aren't under warranty. He also answers my questions and helps me decide when to bring in the Bernina. (I had a few problems last year.) Again, never mess with stuff you don't know for certain or haven't be trained to do. A machine can be knocked out of timing just the slightest (a milisecond) and not run quite right, causing skipped or bad stitches, thread breakage, tension issues, and so on. Also, anytime you bring the machine to a mechanic, bring in the manual, any tools that came with it, and a bobbin of thread. You would do well to thread it before bringing it in so that he can check to make sure you are threading it correctly. Even after all these years of sewing and reading the manual, I threaded my new long-arm wrong--I had never heard of double-looping the thread around the tension, how was I to know to do that? Rich caught it right away and now it sews beautifully. I told him the tension was wrong and I wanted him to set it. Who knows what would have happened had I not left the machine threaded.
Again, thanks for the many responses. And hang in there for answers. My mom is very sick but we'll get to your questions eventually