Model # 3850P Official Chamberlain garage door opener
Here are the diagrams and repair parts for Official Chamberlain 3850P garage door opener, as well as links to manuals and error code tables, if available.
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Model diagram and schematic
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Most common symptoms to help you fix your garage door openers
Choose a symptom to see related garage door opener repairs.
Main causes: faulty logic control board, bad RPM sensor, broken gears in the drive system, bad drive motor…
Main causes: radio interference, weak remote batteries, sunlight interference with safety sensor beams, safety sensors n…
Things to do: check garage door travel, tighten brackets and fasteners, test safety sensors, check travel limits and for…
Main causes: garage door locked, damaged garage door tracks, up-force setting needs adjustment, RPM sensor failure, bad …
Main causes: neighbor's remote programmed at the same time as yours, faulty wall control wiring, bad wall control unit…
Main causes: garage door opener misaligned, travel limits need adjustment, bad travel limit switches, faulty logic contr…
Main causes: safety sensor beams blocked, safety sensors not aligned, downforce setting needs adjustment, damaged garage…
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.
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.…
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.…
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…
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.
Learn about all the convenient features on our Sears PartsDirect website that make your parts purchases easier.…
Get answers to frequently asked questions about Sears and Sears PartsDirect.…
Learn how to open a garage door manually if power to your garage door opener fails.…