Model # 1240R Official Chamberlain garage door opener

Here are the diagrams and repair parts for Official Chamberlain 1240R garage door opener, as well as links to manuals and error code tables, if available.

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Owner’s manual

Error Codes

Model diagram and schematic

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Showing 10 of 63 parts |

Motor unit assembly diagram

Garage door opener drive and worm gear kit (replaces 3002375, 65409)

Part #41A2817

The manufacturer no longer makes this part, and there's no substitute part

Garage Door Opener Rpm Sensor Assembly 41C4398A

#15

Motor unit assembly diagram

Garage door opener rpm sensor assembly

Part #41C4398A

The manufacturer no longer makes this part, and there's no substitute part

#14

Motor unit assembly diagram

Garage door opener limit switch

Part #41D3452

The manufacturer no longer makes this part, and there's no substitute part

#12A

Motor unit assembly diagram

Cover (1246r, 1245r)

Part #41A3583-15

The manufacturer no longer makes this part, and there's no substitute part

Rail assembly diagram

One-piece rail

Part #1707LM

The manufacturer no longer makes this part, and there's no substitute part

Accessories diagram

Multi-function door control panel

Part #78LM

The manufacturer no longer makes this part, and there's no substitute part

Accessories diagram

Remote light control

Part #995LM

The manufacturer no longer makes this part, and there's no substitute part

Motor unit assembly diagram

Gear and sprocket assembly (1256r, 1246r)

Part #41C4206A

The manufacturer no longer makes this part, and there's no substitute part

#12B

Motor unit assembly diagram

Cover (1240r)

Part #41A3583-16

The manufacturer no longer makes this part, and there's no substitute part

#12

Accessories diagram

Remote

Part #973LM

The manufacturer no longer makes this part, and there's no substitute part

Most common symptoms to help you fix your garage door openers

Choose a symptom to see related garage door opener repairs.

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Why doesn't my garage door opener work?

Main causes: faulty logic control board, bad RPM sensor, broken gears in the drive system, bad drive motor…

Why does my garage door opener work intermittently?

Main causes: radio interference, weak remote batteries, sunlight interference with safety sensor beams, safety sensors n…

What preventive maintenance does my garage door opener need?

Things to do: check garage door travel, tighten brackets and fasteners, test safety sensors, check travel limits and for…

Why won't my garage door opener open the garage door?

Main causes: garage door locked, damaged garage door tracks, up-force setting needs adjustment, RPM sensor failure, bad …

Why does my garage door opener open and close by itself?

Main causes: neighbor's remote programmed at the same time as yours, faulty wall control wiring, bad wall control unit…

Why won't my garage door opener fully open or close the garage door?

Main causes: garage door opener misaligned, travel limits need adjustment, bad travel limit switches, faulty logic contr…

Why does my garage door opener reverse on its own?

Main causes: safety sensor beams blocked, safety sensors not aligned, downforce setting needs adjustment, damaged garage…

Why is my garage door opener noisy?

Main causes: loose fasteners, broken brackets, need preventive maintenance, worn drive gears, loose or worn belt, loose …

Most common repair guides to help fix your garage door openers

These step-by-step repair guides will help you safely fix what’s broken on your garage door opener.

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How to replace a chain-drive garage door opener motor

Get your garage door moving again by replacing a defective motor in your garage door opener.…

Repair difficulty

Time required

60 minutes or less

How to replace a belt-drive garage door opener motor

The garage door won't move if the motor is defective. Here’s how to fix it.…

Repair difficulty

Time required

60 minutes or less

How to replace a garage door opener drive chain and cable assembly

If your garage door won’t move, the chain and cable assembly on your garage door opener could be broken. Follow these st…

Repair difficulty

Time required

60 minutes or less

Effective articles & videos to help repair your garage door openers

Use the advice and tips in these articles and videos to get the most out of your garage door opener.

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How to enjoy all the online benefits we offer on our Sears PartsDirect website

Learn about all the convenient features on our Sears PartsDirect website that make your parts purchases easier.…

Top questions about Sears and Sears PartsDirect

How to open a garage door with an opener manually

Learn how to open a garage door manually if power to your garage door opener fails.…

Model # 1240R Official Chamberlain garage door opener

Model diagram and schematic

SEARCH WITHIN THIS MODEL

Most common symptoms to help you fix your garage door openers

Why doesn't my garage door opener work?

Why does my garage door opener work intermittently?

What preventive maintenance does my garage door opener need?

Why won't my garage door opener open the garage door?

Why does my garage door opener open and close by itself?

Why won't my garage door opener fully open or close the garage door?

Why does my garage door opener reverse on its own?

Why is my garage door opener noisy?

Most common repair guides to help fix your garage door openers

How to replace a chain-drive garage door opener motor

How to replace a belt-drive garage door opener motor

How to replace a garage door opener drive chain and cable assembly

Effective articles & videos to help repair your garage door openers

How to enjoy all the online benefits we offer on our Sears PartsDirect website

Top questions about Sears and Sears PartsDirect

How to open a garage door with an opener manually

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