The LiftMaster 045ACT is an OEM replacement logic board for select LiftMaster and Chamberlain AC motor garage door openers that use Security+ 2.0 technology (yellow Learn button). This control board restores core opener functions—motor control, reversing sensor monitoring, wall control operation, and remote/keypad reception—and is designed for North American residential applications using 120V, 60 Hz power. It is myQ enabled, allowing smart control when paired with compatible myQ accessories such as the 828LM Internet Gateway or a myQ hub. The 045ACT platform supports Security+ 2.0 tri-band radio performance for reliable remote control operation and is compatible with Security+ 2.0 transmitters and keypads (e.g., 891LM/893LM remotes and 877LM keypads), helping reduce interference and improve range.
Installation requires disconnecting power, transferring all harnesses and terminal connections (wall control, safety reversing sensors, motor, and limits as applicable), mounting the board, and then reprogramming travel limits and force settings per the opener’s manual. After installation, remotes and wireless keypads must be re-learned using the yellow Learn button on the head unit, and myQ features can be activated by pairing with compatible myQ accessories. For safety and compliance with UL 325, ensure the photo-eye safety sensors are correctly wired, aligned, and tested before normal operation. This board is intended for specific AC chain- or belt-drive models that originally shipped with a 045ACT logic board; it is not for DC motor or built-in Wi‑Fi “W” variants that use different electronics (e.g., 050ACTWF). Always verify compatibility by matching the original board number or consulting the opener’s model documentation.