Jobs at small Fresno companies nobody posts about after 4 years as a web developer

A friend who works at a local manufacturer says there are openings not advertised online. I am in Fresno, in case local advice matters. They like a brief email with a résumé. Should I visit in person?

Thanks for writing this out. I went through something close to it 10 months ago, and it got easier once I kept a simple log of every call and form.