Symptoms and what they usually mean
If the opener hums but the door doesn't move and the door feels light when you lift it by hand (with the opener disconnected), the trolley or carriage assembly is likely the issue — typically a stripped main drive gear in chain-drive units or a snapped belt in belt-drive units.
If the door starts to close then reverses back up, the photo-eye safety sensors are misaligned, dirty, or one of the lenses has lost line of sight. Look for steady LEDs on both sensors — one solid green, one solid red. If either is blinking, that's the problem.
If the door reverses just before fully closing, the close-limit switch is set too far. The opener thinks the door has hit something because it ran out of programmed travel before reaching the floor.
If the opener works intermittently and you hear a faint click without the motor engaging, the start capacitor is failing — a $20 part and a 30-minute job.
Photo-eye safety sensor alignment
The photo-eyes mount about 6 inches off the floor on either side of the door. They send an invisible infrared beam across the opening; if anything breaks the beam during a close cycle, the door reverses. Federal law has required them on every residential opener sold since 1993.
Sensors fall out of alignment from car bumpers, lawn equipment, kids' bikes leaning against them, and even a hard door close shaking the frame. Both LEDs need to be solid — if either blinks, loosen the wing nut, sweep the sensor until both lights are solid, then snug the nut. If the lenses are dusty, wipe with a dry cloth (not Windex).
Limit switch and force adjustments
Modern openers have travel limits set with two screws or buttons on the back of the unit (older Genie and Chamberlain), or learned through a programming sequence on newer LiftMaster and Chamberlain units. If the door doesn't fully close or stops short on opening, the limits need to be re-learned.
Force adjustments tell the opener how much resistance is normal during travel. If force is set too low, the door reverses on its own from drag. If too high, the door won't reverse on contact and becomes a safety hazard.
When the logic board is actually the problem
Logic board failure is real but over-diagnosed. We see it most often after a lightning strike or power surge — common in Kansas during May–August storm season. Symptoms include the unit not responding to remotes or wall button despite power, no LED lights on the head, and burnt-smelling components inside the cover. Replacement boards run $80–$150 plus install.
Before condemning a board, we check the wall-button low-voltage wiring (a stuck contact triggers ghost cycles), the antenna wire (a broken antenna kills remote range), and the wall transformer for openers with separate power supplies.
Brands we service
We carry parts and service all major opener brands: LiftMaster, Chamberlain, Genie, Craftsman (Sears badge of Chamberlain), Marantec, Linear, Liftron, Wayne Dalton iDrive, and legacy Stanley/Sears units that haven't been made in 20 years but are still hanging in plenty of Topeka garages.
Most opener repairs land in the $150–$350 range. If your opener is over 12 years old and has needed two repairs already, we'll be honest about whether replacement is a smarter use of your money.