Opening and closing are different problems. Opening failures are usually mechanical, springs and power. Closing failures are usually the door’s safety systems voting no. Every check below is really the same question asked of a different component: what does the door think is in the way?

Start at the photo eyes

The two small sensors a few inches off the floor on either side of the opening are responsible for most refused closes. The door reverses immediately, or closes only while you hold the wall button down, when the sensor beam is broken or the pair has lost sight of each other.

  • Look for the indicator lights. On most brands, one sensor holds a steady sending light and the other confirms alignment; a dark or blinking light on either end is your answer.
  • Check for the obvious blockers: a rake handle, a bag that slumped over, cobwebs thick enough to read as an obstruction, a trash bin an inch into the beam.
  • Nudge test: the brackets bend easily. A bumped sensor pointing at the floor cannot see its partner. Loosen the wingnut, sight it back at the other sensor until the light steadies, and retighten.

One local wrinkle: on west-facing garages, the low evening sun can blind a sensor directly, and the door refuses to close at exactly the hour everyone comes home. If your door closes fine in the morning and balks on summer evenings, shade the sun-side sensor with a cardboard hood before assuming anything is broken.

Then the floor and the seal

The door decides it has hit something through resistance. Gravel kicked onto the threshold, a garden hose end, a lifted slab edge from frost heave, or a bottom seal stiffened by cold can all read as an obstruction at the last inch, sending the door back up. Sweep the threshold and look at the slab where the door lands. Frost heave is not rare in older DeKalb driveways, and a slab that walked up half an inch over a few winters can be the entire mystery.

Then the travel and force settings

If the sensors check out and the threshold is clean, the opener’s settings may simply be out of date for the door. Two symptoms map to two adjustments:

  • The door closes, then reverses off the floor as if it changed its mind: the close-travel limit is set long, so the opener presses the door into the slab and interprets the resistance as an obstruction.
  • The door reverses at the same mid-travel point every time: something mechanical binds there, or the close force is set too sensitive to get past normal stiffness.

Settings drift matters more in unheated garages, because a door is genuinely stiffer at 10 degrees than it was at the August afternoon when the installer dialed it in. These adjustments are screws or menu buttons on the opener head, and the manual for your model is worth the search. Adjust in small steps; force settings exist to keep the door from crushing things, and cranking them to maximum defeats the sensor system you just verified.

When mid-travel reversing is the track’s fault

A door that binds at the same spot has a reason there: a flattened roller, a track dented by a car mirror (the standard injury in the alley garages of DeKalb’s older blocks), or track brackets loosened until the rails pinch. Look at the spot where the door hesitates. Shiny scrape marks on the track or a roller that does not spin with the door are the tell. That repair is ours, and if the door is visibly crooked or a cable has come off its drum, stop cycling it entirely; each attempt makes the recovery job bigger.

The version that is an emergency

A door that will not close is a security problem by bedtime. If you have run these checks and the door is still open, tell us that when you call; an open garage moves you up the day’s schedule the same way a trapped car does. And if the door slammed itself shut hard at any point in this story, read the spring guide before doing anything else; slamming is how a broken spring announces itself.