Realigning photo-eye sensors is something most owners can do without a truck roll. Both sensors should have small LED lights that glow steady; if one blinks, loosen its mounting screw, nudge it until the light holds steady, and retighten. Wipe the lenses with a dry cloth first; dust blocks the beam just as well as a misaligned eye does. Checking remote batteries and resetting the wall console's code are also fair game before you call anyone. What you shouldn't touch: the logic board itself, the drive gear housing, or anything involving the opener's internal wiring. Openers from the early 2000s often used proprietary boards that aren't interchangeable with later replacement parts, and cracking one open to diagnose it usually turns a repairable unit into one that needs full replacement. If the opener trips the garage circuit breaker repeatedly, stop and call - that's a wiring issue, not a settings issue, and it's not a DIY afternoon.