Sears Craftsman 1D7675 / LiftMaster 45ACTMC Receiver Logic Board Assembly is a replacement receiver logic board application for select garage door openers in the LiftMaster, Chamberlain, and Sears Craftsman family. It is used to restore the opener control logic, receiver programming, learn button functions, and related low-voltage control operation when the original board has failed.
Compatibility and Application
This part should be selected by the original board number and opener model, not by appearance alone. Many LiftMaster, Chamberlain, and Craftsman boards look similar but use different drive types, frequencies, learn button colors, and housing layouts.
- Sears Craftsman 139.54985 and 139.54990 applications where the original board matches the 1D7675 / 45ACT family
- Select LiftMaster and Chamberlain AC chain or belt drive openers manufactured after 2011 that use the yellow learn button board family
Features and Specifications
| Feature / Specification | Details |
|---|
| Manufacturer | Liftmaster |
| Product Type | Receiver logic board assembly |
| Part Number | 45ACTMC / 1D7675 |
| Application | Select Sears Craftsman, LiftMaster, and Chamberlain residential AC chain and belt drive openers |
| Compatible Operator Type | AC chain drive and AC belt drive garage door openers |
| Frequency / Technology | Security+ 2.0 tri-band style applications |
| Learn Button Color | Yellow learn button |
| Notes | Model, generation, and original board number must match before ordering. |
Also Known As / Related Part Numbers
- 45ACTMC
- 045ACTMC
- 45ACT
- 045ACT
- 1D7675
- 041D7675
- 001D7675
- 041D7656
- 41D7656
Technician Note
Before replacing a logic board, confirm that the opener has proper power, the safety sensors are aligned, the wall control wiring is not shorted, and the original board has not failed because of an outside wiring or surge issue. A replacement board may require remotes and keypads to be programmed again after installation.
Before Ordering Checklist
- Match the original board number printed on the control board or end panel label.
- Confirm the opener model number and parts diagram before ordering.
- Confirm the learn button color and radio technology match the replacement board.
- Do not substitute similar-looking 41AB, 41AC, 41AS, 41DB, 45ACT, or 45DCT boards without confirming the exact family.
- Inspect for moisture, surge, burn marks, damaged wiring, or failed accessories that may have caused the original board failure.
Professional Advisory
Disconnect power before service. If the opener has burn marks, damaged line-voltage wiring, water intrusion, repeated fuse or board failures, or unsafe door movement, have the operator inspected by a qualified garage door technician. Do not bypass required safety devices to make an opener run.
Product Questions and Answers
Is the 1D7675 board the same family as LiftMaster 45ACTMC?
Yes. The 1D7675 reference is commonly associated with the LiftMaster 45ACT / 45ACTMC Security+ 2.0 receiver logic board family. Match the number on the original board before ordering.
What learn button color should this board be used with?
This board family is used with select yellow learn button Security+ 2.0 garage door openers. It is not for older purple, red/orange, green, or dip-switch systems.
Will this work with Craftsman 139.54985 or 139.54990?
It may be used with those Craftsman applications when the original board and parts diagram call for the 1D7675 / 45ACT style board.
Do remotes need to be reprogrammed after replacing this board?
Yes. Remote controls and wireless keypads usually need to be relearned to the new receiver logic board after installation.
What symptoms can point to a bad receiver logic board?
Common symptoms include no response from remotes, a failed learn button, intermittent operation, or visible board damage, but power, sensors, wall controls, and wiring should be checked first.
