background image

6  Testing & Adjusting the Door Force Safety System

The door force adjustments are located on the side of the opener. 

The door force adjustments must be properly 

set at all times. 

The CLOSE FORCE adjustment controls how much force is required to cause the door to reverse 

direction if an obstruction is encountered during closing. The OPEN FORCE adjustment controls how much force 
is required to stop the door if an obstruction is encountered during opening.

➤ 

NOTE:

 Read the following directions carefully before 

changing the door force adjustments. 

Door Force Safety System Test

1

  Start with the door open. 

Use the remote control to 

cycle the door during this test.

 

Adjusting the Close Force

2

  Turn the CLOSE FORCE adjustment 1/8-turn at a time 

in the DECREASE direction (counterclockwise) until 
the door stops and reverses mid travel while going 
down.

3

  Turn the CLOSE FORCE adjustment 1/8-turn at a time 

in the INCREASE direction (clockwise) until the door 
fully closes without reversing.

 

Safety Reversal System Test

4

  Lay a 2 x 4 board fl at on the fl oor where it will be struck 

by the 

center

 of the door as it closes.

5

  Verify that the door reverses when it strikes the board. 

The door 

must

 reverse within two seconds after 

striking the board.

➤ 

NOTE:

 If the door stops after encountering the board 

and does not reverse, the CLOSE FORCE needs to be 
DECREASED.

6

  Repeat the Safety Reversal System Test until the door 

reverses within two seconds of striking the board.

 

Adjusting the Open Force

7

  Turn the OPEN FORCE adjustment 1/8-turn at a time 

in the DECREASE direction (counterclockwise) until 
the door stops mid travel while going up.

8

  Turn the OPEN FORCE adjustment 1/8-turn at a time 

in the INCREASE direction (clockwise) until the door 
fully opens without stopping.

7  Replacing the Opener’s Lamp

If the opener’s safety lamp fails to light manually or when 
the opener is cycled, the light bulb needs replacing. Use 
the following steps to replace the light bulb.

1

  Swing the light cover open to expose the light bulb and 

lamp socket.

2

  Replace the light bulb with a 100 watt maximum rough 

service bulb (sometimes called a garage door bulb).

3

  Swing the light cover closed, snapping it shut.

4

  Press the wall station’s lamp button to test the lamp.

8 Troubleshooting

LAMP FLASHES 

TROUBLE CODE

PROBLEM

CAUSE

REMEDY

1 FLASH

No problem

Remote control entered into 
memory

Add any additional remote controls 
(MegaCode™ type only)

2 FLASHES

Door won’t close

Shorted wall station wires

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

3 FLASHES

Door won’t close

Safety beam obstacle

Check for obstacles. Align the safety beam 
(Section 4)

4 FLASHES

Door reverses 
or won’t open or 
close

Open or Close force 
exceeded, or motor thermal 
shutdown

Check for binding or un-balanced door. 
Adjust the door force (Section 6). If motor had 
thermal shutdown, wait 30 minutes and retry.

5 FLASHES

Door won’t open 
from transmitter

Remote was activated while 
vacation switch was locked

Unlock vacation switch on wall station

6 FLASHES

Motor ran longer 
than 30 seconds

Mechanical or electronic 
failure

Call your local garage door professional

FCC NOTICE

Changes or modifi cations not expressly described in this manual or approved by the manufacturer could void the user’s authority to operate the 
equipment. This device complies with FCC Part 15. Operation is subject to the following two conditions: (1) This device may not cause harmful 
interference and (2) this device must accept any interference received, including interference that may cause undesired operation.

LIMITED WARRANTY

This Linear product is warranted to the original consumer against defects in material and workmanship for:

 MODEL 

ELECTRONICS 

MECHANICAL 

MOTOR 

BELT

 LDO50 

year 

years 

Lifetime 

Lifetime

 

LDO33 

1 year 

5 years 

10 years 

Lifetime

This product is warranted to the original consumer against defects in material and workmanship for the periods mentioned above. Linear 
will repair, or at its option, replace, any device that it fi nds requires service under this warranty, and will return the repaired or replaced 
device to the consumer at Linear’s cost. Devices must be sent to Linear for service at owner’s expense. This warranty does not apply 
to damage to the product from negligence, abuse, abnormal usage, misuse, accidents, normal wear or tear or due to failure to follow 
Seller’s instructions, or arising from improper installation, storage or maintenance. In no event will Linear be responsible for incidental, 
compensatory, punitive, consequential, indirect, special or other damages. The remedies provided by this warranty are exclusive. Some 
states do not allow the exclusion or limitation of incidental and consequential damages, so the above limitation or exclusion may not apply 
to you. Any warranties implied by law are limited to the time periods set forth above. Some states do not allow limitations on how long an 
implied warranty lasts, so the above limitation may not apply to you. This warranty gives you specifi c legal rights, and you may also have 
other rights which vary from state to state.

For warranty service and shipping instructions contact Linear at the phone number shown below. In order to be protected by this warranty, 
save your proof of purchase and send a copy with equipment should repair be required. All products returned for warranty service require 
a Return Product Authorization Number (RPA#). Contact Linear Technical Services at 1-800-421-1587 for an RPA# and other important 
details.

4  Testing the Infrared Safety Beam

The safety beam has two components, a sender and a receiver. The sender produces a narrow infrared beam that 
travels across the bottom of the door opening to the infrared receiver. If an object blocks the infrared beam while the 
door is closing, the door will stop, then reverse and fully open (the opener’s light will fl ash three times).

As a safety feature, the opener will ignore signals from all remote controls if the door is open and the 
infrared safety beam is blocked or out of alignment. In this case, the door can be forced closed by pressing 
and holding the wall station’s up/down arrow pushbutton (be sure the door area is in clear view).

Safety Beam Test

1

  Check that the opener has power. The green lights on 

the sender and receiver should be lit.

2

  If the receiver’s green light is on, but the red light is off, 

the receiver has power but is not detecting the infrared 
beam from the sender. The red light might fl ash when 
the beam is partially detected. This can be caused by 
mis-alignment or something blocking the beam. Adjust 
the safety beam sender and receiver while watching the 
receiver’s red light (stay out of the beam while aligning 
it). When the red light stays on, the beam is aligned.

SAFETY BEAM INDICATOR TABLE

GREEN ON

POWER ON

GREEN OFF

POWER OFF

RED ON

BEAM OK - NO BLOCKAGE

RED OFF

BEAM BLOCKED OR MIS-ALIGNED

RED FLASHING

BEAM ALIGNED POORLY

➤ 

NOTE:

 If the receiver’s red light remains off, check 

for: 1) Dirt on the receiver’s lens, 2) Sunlight shining 
into the receiver’s lens, 3) A short in the safety beam 
wiring (from staples or at the opener terminals).

3

 

With the door closed and the opener disengaged 
from the door,

 press the wall station’s UP/DOWN 

ARROW button to move the traveler (the part on the 
belt or chain that the trolley engages with) to the up 
position (away from the door).

4

  Push the wall station’s UP/DOWN ARROW button again. 

While the traveler is moving to the down position (toward 
the door), block the safety beam.

 THE TRAVELER 

MUST STOP, THEN REVERSE TO THE UP POSITION.

 

The opener’s light should fl ash three times.

5

  Place an object in the path of the safety beam. Check 

that constant pressure is required on the wall station’s 
UP/DOWN ARROW button to cause the traveler 
to move toward the down position. Release the 
pushbutton 

before

 the opener stops; check that the 

traveler returns to the up position.

➤ 

NOTE:

 The garage door opener will not respond to a 

CLOSE command from a radio transmitter if the safety 
beam is blocked.

6

  To reconnect the opener, fl ip the release lever up. 

Raise the door manually until the opener reconnects.

5  Adjusting the Open and Close Limits

The limit adjustments that control how far the door will 
open or close are located on the side of the opener. The 
limits should be adjusted so the door opens just short of 
any door stops, and closes right at the fl oor level. Each 
full turn of a limit adjustment equals about 2-½” of door 
travel.

1

  Start with the door in the closed position.

2

  Activate the remote control. Wait while the door moves 

to the open position and stops.

3

  Examine the position of the door.

  • If the door needs to open 

more

, turn the OPEN 

LIMIT adjustment clockwise ¼-turn (towards UP on 
the label) to raise the open limit.

  • If the door needs to open 

less

, turn the OPEN LIMIT 

adjustment counterclockwise ¼-turn (towards DOWN 
on the label) to lower the open limit.

➤ 

NOTE:

 On jamb doors, set the open limit so the door 

stops just short of level (see fi gure).

4

  Activate the remote control. Wait for the door to move 

down a few feet, then activate the remote control again 
to stop the door.

5

 Repeat Steps 2-4 until the open limit is properly 

adjusted.

6

  Activate the remote control. Wait while the door moves 

to the closed position and stops.

7

  Examine the position of the door.

  • If the door needs to close 

more

, turn the CLOSE 

LIMIT adjustment counterclockwise ¼-turn (towards 
DOWN on the label) to lower the close limit.

  • If the door needs to close 

less

, turn the CLOSE 

LIMIT adjustment clockwise ¼-turn (towards UP on 
the label) to raise the close limit.

8

  Activate the remote control. Wait for the door to move 

up a few feet, then activate the remote control again to 
stop the door.

9

 Repeat Steps 6-8 until the close limit is properly 

adjusted.

➤ 

NOTE:

 If the door stops during opening or reverses 

during closing before reaching the limits, the door force 
adjustment needs to be set. Change the adjustment as 
described in the next section then return to this step to 
fi nish setting the limits.

  CAUTION 

Set the open and close limits carefully. Setting 
the limits beyond the distance that the door can 
travel could cause damage to the door, the door 
hardware, or opener.

 WARNING 

Too much door force will interfere with the 
proper operation of the safety system. SOMEONE 
COULD BE SERIOUSLY INJURED OR KILLED IF THE 
DOOR FORCE IS SET TOO HIGH. A closing door 
might not reverse properly when required and 
someone could be pinned under it. An opening 
door might not stop when going up and someone 
hanging on the door could get pinned between 
the door and the header. Do not increase the 
door force beyond what is required to move the 
door. DO NOT USE THE DOOR FORCE ADJUSTMENT 
TO COMPENSATE FOR A BINDING OR STICKING 
GARAGE DOOR. PERFORM THE SAFETY REVERSAL 
SYSTEM TEST (STEPS 4-6) MONTHLY!

Copyright © 2007 Linear LLC 

223710 B

PRINTER’S INSTRUCTIONS:

INSTR,HOMEOWNERS,LDO W/MCT3; LINEAR P/N: 223710 B; INK: BLACK; MATERIAL: 20# MEAD BOND; SIZE: 11.000” x 17.000”; FOLDING: 1-FOLD VERTICAL, 1-FOLD HORIZONTAL, FINISH 8.500” X 5.500” WITH LOGO SHOWING; SCALE: 1-1; SIDE 2 OF 2 

S

AFETY BEAM INDICATOR

S

RED LIGHT

GREEN LIGHT

GREEN LIGHT

ON = POWER ON
OFF = POWER OFF

RED LIGHT

ON = BEAM ALIGNED, NO OB

S

TRUCTION

OFF = BEAM NOT ALIGNED, OR OB

S

TRUCTION

BLINKING = BEAM NEED

S

 BETTER ALIGNMENT

ADJU

S

T THE 

S

ENDER

AND RECEIVER UNTIL
THE RED INDICATOR
LIGHT

S

 

S

OLID

ADJU

S

TING THE BEAM

BLOCK THE BEAM
WHILE THE TRAVELER
I

S

 MOVING DOWN

TOWARD
DOOR

TOWARD
OPENER

UP

DOWN

CHECKING FOR REVER

S

AL

TRAVELER

THE TRAVELER MU

S

T REVER

S

E

WHEN THE BEAM I

S

 INTERRUPTED

PLACE AN OBJECT
IN THE BEAM'

S

 PATH

VERIFY THAT CON

S

TANT

PRE

SS

URE I

S

 REQUIRED

ON THE WALL 

S

TATION'

S

PU

S

HBUTTON TO MAKE

THE TRAVELER GO DOWN 

RELEA

S

E PU

S

HBUTTON

BEFORE THE OPENER 

S

TOP

S

,

THE TRAVELER 

S

HOULD

RETURN TO THE UP PO

S

ITION

CHECKING FORCED CLO

S

URE FEATURE

 WARNING 

With the door closed, disengage the trolley 
from the chain during these alignment tests by 
pulling the red release handle.

 WARNING 

Serious injury or death from a closing garage 
door may result because of failure to test and 
adjust safety reverse system. Repeat this test 
monthly and adjust as needed.

U

S

E A 

S

CREWDRIVER

TO ADJU

S

T THE LIMIT

S

ETTING THE OPEN LIMIT

OPEN LIMIT

ADJU

S

TMENT

UP

DOWN

CLO

S

E LIMIT

ADJU

S

TMENT

UP

DOWN

U

S

E A 

S

CREWDRIVER

TO ADJU

S

T THE LIMIT

S

ETTING THE CLO

S

E LIMIT

DOWN

UP

EXAMINE THE 

S

POT WHERE

DOOR 

S

TOP

S

 CLO

S

ING

CHECKING WHERE THE DOOR 

S

TOP

S

DOWN

UP

EXAMINE THE 

S

POT WHERE

THE DOOR 

S

TOP

S

 OPENING

CHECKING WHERE THE DOOR 

S

TOP

S

ADJU

S

TING THE CLO

S

E FORCE

ADJU

S

TING THE OPEN FORCE

S

ETTING THE DOOR FORCE

CLO

S

E FORCE

DECREASE

DECREA

S

E CLO

S

E FORCE

ADJU

S

TMENT UNTIL THE

DOOR REVER

S

E

S

 MIDWAY

WHILE GOING DOWN

UNDER-

S

ETTING THE CLO

S

E FORCE

TE

S

T WITH 

S

MALL OB

S

TACLE

THE DOOR MU

S

T REVER

S

E

WITHIN 2-

S

ECOND

S

 AFTER

IMPACT WITH A 2 x 4 BOARD

2 x 4 BOARD LAID FLAT
UNDER CENTER OF DOOR

TE

S

TING THE 

S

AFETY REVER

S

AL 

S

Y

S

TEM

OPEN FORCE

DECREASE

DECREA

S

E OPEN FORCE

ADJU

S

TMENT UNTIL THE

DOOR 

S

TOP

S

 MIDWAY

WHILE GOING UP

OPEN FORCE

INCREASE

INCREA

S

E OPEN FORCE

ADJU

S

TMENT UNTIL THE

DOOR OPEN

S

 FULLY

WITHOUT 

S

TOPPING

UNDER-

S

ETTING THE OPEN FORCE

S

ETTING THE OPEN FORCE

CLO

S

E FORCE

INCREASE

INCREA

S

E CLO

S

E FORCE

ADJU

S

TMENT UNTIL THE

DOOR CLO

S

E

S

 FULLY

WITHOUT REVER

S

ING

S

ETTING THE CLO

S

E FORCE

IN

S

TALL NEW BULB (UP TO 100 WATT

S

)

REPLACING LAMP

S

WING COVER OPEN

 WARNING 

Always perform the Door Force Safety System 
Test after making any adjustments to the 
opener.

S

ETTING THE OPEN LIMIT ON A JAMB DOOR

JAMB DOOR

S

ET THE OPEN LIMIT 

S

O THE DOOR

S

TOP

S

 JU

S

S

HORT OF LEVEL

NOTE: SETTING THE OPEN LIMIT TOO HIGH WILL CAUSE
THE OPENER TO "BUCK" WHEN STARTING DOWN

Reviews: