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Bearcat Company - Linear Trouble Shooting

Linear Garage Door Opener Trouble Shooting

Garage Door Openers - USA has placed some basic Linear garage door opener trouble shooting for those that seek a little help before calling the manufacture or a local garage door repair service company. Remember Safety First.

  General Troubleshooting

The most important step in servicing the garage door opener is the isolation of the faulty section.
The technician must decide if the problem is in the:
  • Installation
  • Opener Mechanism
  • Remote Control
  • Radio Receiver/Control Circuit


The opener should be installed in such a manner as to provide smooth operation.
  • Any "jumping" of the door and hardware on initial movement, could mean that the opener mechanism is pushing or pulling at the wrong angle -- check the installation.
  • Disconnect the trolley by pulling the manual release of the opener and move the door by hand to ensure that the door is balanced. A weak spring could mean that the opener is required to to lift the weight of the door. The opener may be capable of doing this, but a most important feature will be lost -- SAFETY. Any major door repairs should be completed prior to the installation.

Opener Mechanism

Disconnect all control wires, but not the sensor wires, at the rear or side of the opener and momentarily short the COMMON and PUSHBUTTON terminals together (with a small jumper wire). The opener should operate if no problem exists. If the opener does not function use the troubleshooting chart.

Solid State Microprocessor Control Board

The Linear LSO33, LSO50, LDO50 incorporate self-diagnosing capabilities to a point. A diagnostic "flashing LED" found next to the "learn button" can be used to troubleshoot some problems with the opener. The chart below will assist in isolating the most common electrical difficulties.

# of flashes








No problem

Door wont close

Door wont close

Door reverses or wont open or close.

Door wont open from hand held transmitter(s).

Motor runs longer than 30 seconds.


Add any additional remote controls (MegaCode type only).

Check wall station wires. Be sure both are connected to the terminal screw. Check for a staple in the wall station wires. Remove any staples compressing the wire.

Check for obstacles. Align the safety beams.

Check for binding or un-balanced door. Adjust the door force if neccessary. If motor had a thermal shutdown wait 30 minutes and retry.

Unlock vacation switch on wall station.

Call a local garage door professional.

  Troubleshooting Symptom Diagnosis

Warning: Always disconnect power to garage door opener before removing or installing outside cover !

1. Garage door opener does not operate from door control push button or remote control:     
  • No power. Check to make sure the outlet has power. Plug in the opener. There may be a light switch that turns the outlet "On" make sure that it is on. Also check fuse box or circuit breaker.
  • Overload protector tripped in motor. wait 15 minutes, after the motor has cooled down try to operate again.
  • Shorted door control or shorted bell wire. Remove wires and retest. Repair bell wire or door control

2. Door operates from door control push button, but not from the remote control:     
  • Remote control battery may be dead. Change battery and try again.
  • Remote control may not be sending a signal. If more than one remote, check that both are working.
  • Lock switch is ON. If so push lock button to turn OFF.
  • Code remote control to receiver.

3. Garage door opener operates from door remote control, but not door control push button:     
  • Door control may be defective. Disconnect wires from door control, short white and white/red wires to see if the unit operates. If the unit works replace the door control.
  • Open bell wire. Disconnect wires from the control board, short white and red terminals to see if the unit operates. If the unit works replace/repair the bell wire.

4. Remote control has short range:     
  • Weak battery. Replace battery and try again. If two remotes are available, try both for comparison.
  • Remote to close from inside roof of car. Pull the visor down and retest. If the unit operates, the visor will have to remain down when using the remote.
  • Metal door or siding. Open garage door if the range increases, Try inceasing Antenna wire length
  • RF interference may be causing the problem.
  • Possible defective control board. ( rare )

5. Garage door opener does not shut of at the end of travel:     
  • Check limit travel adjustment first.
  • Limit contacts not operating. Remove cover and manually observe the switch assembly. Check continuity of contacts. Possible bad assembly.
  • Check gear and sprocket assembly for wear. Check shaft for play or wobble. Worn assembly can cause unit to go out of sync.

6. Garage door opens and/or closes by itself:     
  • Stuck remote control button. Check all remotes. check LED on receiver.
  • Staples around Wall Station bell wire could be cutting into that wire. Remove wires from opener and test. Replace staples causing intermittent short.
  • Wall station could have sticking door control push butoon. Remove wires from control panel and test. Replace wall station if defective.

7. Motor hums, will not run:     
  • Trolley jammed into maximum opened or closed rail travel. Visually check location of trolley. Repair as necessary and readjust limits.
  • Defective capacitor. Subsitute a known good capacitor. Replace if problem fixed.
  • Defective wiring or connector(s) in capacitor circuit. Check for continuity. Repair wire or connector(s).
  • Defective motor bearings. Remove motor, try to turn shaft by hand. If the shaft will not turn freely, replace the motor.

8. Full force is applied before door will reverse:     
  • Force control out of adjustment. Decrease force by turning control counter clockwise.
  • Defective control board. Replace and retest.

9. Door closes completely and immediately opens fully:     
  • Down travel improperly adjusted or defective. Adjust the Down limit and retest. If the limit assembly is defective replace.
  • Obstruction causing door to reverse. Pull emergency release. Open and close the door manually while checking for obstruction. Remove obstruction.
  • Defective door hardware causing the door to reverse. Open and close the door manually while checking for defective hardware. May require the service of a garage door professional.
  • Ice or snow buildup under door. Inspect the area around the base of the door and look for any ice or snow buildup. Remove buildup. If limit switch is adjusted to compensate for buildup, door will not close fully when ice or snow has melted.
  • Gear assembly wearing. Remove cover and inspect for wear and plastic shavings. This influences the sync of the door and opener. Replace gear with kit or assembly.

10. Door starts to open/close only travels 8" then reverses/stops:     
  • Forces for up/down set to low. Pull emergency release and check manual door operation. If no obstruction, increase force and retest.
  • Defective control board. Replace and test.

11. Door does not close, light on garage door opener flashing:     
  • Check the safety beams. Both beams must be aligned or aimed across the door opening without any beam obstruction. Remove any obstruction or align both beams.
  • Check for spider webs and/or dirty lenses. Wipe clean.
  • Cheack status of both LED lights on each beam housing.
  • Check safety sensor wiring and connections to the power head unit. Repair as necessary.
  • Check for diagnostic flashing code "3". Located at the power head unit.
  • Check safety beam indicator table below to aid in troubleshooting.
  • Try replacing safety beams. Retest.

12. The motor runs but the door does not move:     
  • Check to see if trolley is disengaged into manual mode. Reconnect for automatic operation.
  • Check for a stripped helical or worm gear(s). Replace parts as necessary.

13. Door does not close completely:     
  • The travel limits may need to be adjusted. Pull emergency release and check door travel to ensure that it operates smoothly. If so, adjust travel limits.
  • Door may be obstructed. Remove obstruction.
  • Check limit switch contacts and limit assembly. Replace if necessary.

14. Door does not open completely:     
  • Is something obstructing the door? Is it out of balance, or is there a broken spring? Remove the obstruction. Repair broken spring or balance the door properly.
  • If the garage door is in good working order but still doesn't open all the way, increase the up force.
  • If the garage door openers at least five feet, the open travel limit may need to be increased. One turn equals approximently 2 inches of travel. Repeat the safety reverse test after the adjustment is complete.

15. Light does not go on when door opens:     
  • Light bulb could be out. Inspect light bulb and replace if necessary.
  • Light socket could be damaged. Check for voltage where the light socket leads connect to the terminal board.
  • Defective control board. Unplug and plug back in AC cord. Listen for relay click on control board. If click is heard, check for defective socket or wiring.

16. Light does not go OFF after delay period:     
  • Work light switch "on". Turn off work light switch.
  • Defective wall station. Replace wall station.
  • Defective control board. Replace defective control board if necessary.

17. Garage door opener strains or needs maximum force to open and close:     
  • The garage door may be out of balance or a spring may be broken. Close the door and use the emergency release handle to disconnect the trolley. Open and close the door manually. A properly balanced door should stay at any point of travel while being supported entirely by it's spring(s). If it does not, disconnect the garage door opener and call a garage door professional. Do not increase force to operate the garage door opener.







  Power On

  Power Off

  Beam Ok-No Blockage

  Beam Blocked or Mis-aligned

  Beam Aligned Poorly.