LiftMaster Opener Error Code MAS 4 blinks: Meaning and Fix
Also shown as: MAS flashes four times
Reading the opener display
A garage door opener reports faults through blinking LEDs on the motor head, a diagnostic window on the logic board, or the wall control. Count the flashes slowly and repeat the count before you decide what you saw. On LiftMaster the Learn button color and the count of flashes together identify the board.
LiftMaster, from the Chamberlain Group, is the professional-installer line. Its openers with a yellow Learn button report faults as LED flash counts or two-digit diagnostic codes such as 1-1 or 4-5 on the logic board. The codes apply to model numbers such as 8500W and 87504-267; check the label on your unit to confirm yours.
What causes MAS 4 blinks
- Bent tracks
- An obstruction stopping the door closing
- A damaged or disconnected RPM sensor
How to fix it
- Disconnect power.
- Check the RPM sensor wiring and connector.
- Check the door travels freely.
- Replace the sensor if damaged.
- Restore power and test.
Parts you may need
| Part | Part no. | Buy |
|---|---|---|
| Receiver logic board, 315MHz | 041DS002-2 | Find part |
Part numbers are OEM references; confirm fit by your model number before ordering. Some links are affiliate links; we may earn a commission at no extra cost to you.
Questions
What does MAS four blinks mean?
An RPM sensor error.
Cause?
Bent tracks or a bad sensor.
Fix?
Check wiring, then replace the sensor.
Other LiftMaster opener codes
Sources
Part numbers are OEM references; confirm fit by your model number before ordering. Meanings compiled from manufacturer and parts-retailer documentation; see sources below. Unplug the appliance before opening it.
Applies to models including 8500W, 87504-267, LJ8900W, 2265, 2280, 1240R, 1345, 8075.