The 5-minute troubleshoot
Before you pick up the phone, work through these five checks in order. Statistically, three out of every four 'won't close' callouts we attend turn out to be cause #1 or cause #2 — both of which the homeowner could have resolved in 60 seconds.
1. Check the safety photo-eye sensors
Look at the floor on each side of the garage door opening. About 15cm up from the ground, mounted on the vertical track, you'll see two small black or chrome sensors facing each other. These shoot an invisible infrared beam across the opening. If the beam is broken — by misalignment, a spider web, dirt on the lens, a stored item, or a bumped sensor — the opener refuses to close.
Each sensor has a small LED on it. On B&D, Merlin and ATA units, both LEDs should be steady green (or steady red on some older units — the key word is steady). If either is off, flashing or weak, gently re-aim the sensors at each other, wipe the lenses with a clean dry cloth, and re-tighten the mounting brackets. Cost to fix yourself: $0. Time: under 1 minute.
2. Look for obstructions in the track or weather seal
Run your eye down both vertical tracks looking for anything jamming the rollers — a bolt, a stray cable, a piece of garden cane that's fallen against the track, or a kinked weather seal at the bottom rail. Sectional doors particularly suffer from leaves, gum nuts and small debris collecting in the bottom track and physically blocking the door from seating to the floor.
Sweep out the floor track, gently flex the bottom rubber seal to confirm it's not folded under itself, and try closing again. Cost to fix yourself: $0. Time: 2 minutes.
3. Check the down-limit and force settings
Garage door openers have two adjustments: down-limit (how far the door travels before the opener stops) and down-force (how much resistance the opener tolerates before deciding it's hit something). If the door stops 5–10cm short of the floor, the down-limit has likely drifted slightly. If the door touches the floor and bounces back up, the down-force is set too sensitive.
Most modern openers have small adjustment dials on the motor head — usually labelled with arrows. A quarter-turn in the right direction often resolves the issue. If you're not confident which dial is which, leave it to a tech: incorrect adjustment can mask a more serious mechanical issue or cause the door to slam shut. Cost to fix yourself: $0 (or $220 for a service if unsure). Time: 5 minutes.
4. Inspect the lifting cables
With the door fully open, look at the steel cables running from a drum at each end of the spring shaft down to the bottom of the door. They should be taut and intact. Fraying, kinks, or one cable visibly slack while the other is tight indicates cable failure or a starting-to-fail cable.
A cable that's actively snapped will leave the door sitting crooked — one side higher than the other when closing. This is a stop-using-the-door issue. Lifting cables hold the entire weight of the door against the springs and a snapped cable mid-cycle is genuinely dangerous. Call us. Cable replacement is routine — $250–$450 in most cases. Cost: tech callout. Time: stop and call.
5. Check for bent or kinked tracks
Walk along both vertical tracks looking for visible bends, dents or kinks — usually caused by a vehicle bump or a heavy object leaning against the track. Even a small kink can prevent the rollers from passing through cleanly and stop the door from completing its travel.
Track straightening or section replacement is $200–$500 depending on severity and is a tech job — bent track sections need to be removed, straightened or replaced, and the whole door re-aligned. Cost: tech callout.
Quick troubleshooting flow
Run through it like this: Sensor LEDs both steady green? → No: realign sensors. → Yes, but still won't close? Track clear of obstructions and weather seal sitting flat? → No: clear and re-test. → Yes, but still won't close? Door stops 5cm short or bounces back at floor? → Yes: down-limit / down-force adjustment needed (call us if unsure). → Door sitting crooked or one side higher than the other? → Yes: cable failure — stop and call. → Visible kink in either vertical track? → Yes: bent track — call us.
When to call us
Call (07) 4615 4481 if:
- Sensors look fine and there's no obstruction, but the door still won't close.
- You can see fraying or damage on the lifting cables.
- The door is sitting crooked when closing.
- You can see a visible bend or kink in either track.
- The opener motor is straining loudly — see also our grinding noise guide.
Won't-close callouts are usually scheduled same-day or next-day across Toowoomba and surrounds. After-hours emergencies (vehicle stuck inside, security risk) are covered on 0450 382 646.

