LiftMaster K75-12489 MT Auto Reversal System Logic Board
LiftMaster K75-12489 MT Auto Reversal System Logic Board
The LiftMaster K75-12489 is the Auto Reversal System, or ARS, logic-board service reference identified in the documented MT commercial-door operator electrical arrangement. It is a specific replacement PCB rather than a complete electrical box or a universal commercial-door controller. Match the installed operator and control revision before ordering this legacy electronics component. Select the replacement by the complete part number and the installed equipment configuration. A similar photograph or a shared LiftMaster brand name does not establish interchangeability. Confirm the applicable service drawing before ordering so the repair addresses the correct component and its related mounting, connection and operating requirements.
Compatibility — Models, Versions and Exclusions
| Model or selection point | Compatibility requirement |
|---|---|
| Documented MT electrical arrangement | Confirm the K75-12489 ARS board callout. |
| Other MT revisions | A shared model family does not establish a current board match. |
| Complete electrical box | Separate package with additional components. |
| Modern controller conversion | No universal upgrade or monitored-device conversion is established. |
Identify the Assembly and Plan the Repair
An automatic-reversal complaint may involve the board, connected wiring, feedback or door condition. Have a trained door technician identify the fault before replacing the PCB. Compare the old board markings and connections with the exact service drawing and confirm that the remaining circuitry is suitable for the approved replacement.
The ARS description does not replace the need for the operator’s required safety equipment or approved operating mode. Do not promise new functions or use board service as an improvised control conversion. Confirm the current board and mounting package, restore the prescribed setup and test the required reversing, stopping and protection functions before returning the door to use.
An electrical symptom does not identify the failed component by itself. Have qualified service personnel inspect the supply, wiring, connections and equipment condition before replacing parts. Record existing labels and terminal references with power safely isolated. A replacement should restore the documented circuit arrangement; it should not be used to change operating voltage, defeat a protective function or compensate for a mechanical load that the equipment cannot safely move.
Specifications and Product Identification
| Specification | Details |
|---|---|
| Ordering reference | K75-12489 |
| Component | Auto Reversal System logic board / PCB |
| Documented context | MT commercial-door operator |
| Separate limit components | Limit shaft and limit-switch assemblies use their own references |
| Selection requirement | Exact control revision and current service recommendation |
Before Ordering
- Record the full MT and existing board identification.
- Match the ARS PCB reference and control revision.
- Inspect wiring, feedback and mechanical door condition.
- Plan the required setup and reversal/protection tests.
Package Contents and Separate Requirements
This offer identifies the ARS logic-board service component. A complete electrical box, transformer, limit mechanism, photo-eye set, motor and commercial-door operator are not established as included. Confirm current board mounting and connection pieces after the actual failure and exact service application have been verified.
Safety Warnings — Read Before Installation or Service
- WARNING: Electrical service can expose hazardous voltage and moving equipment. Use qualified service personnel and electrical personnel where required.
- Disconnect every applicable mains, battery and auxiliary supply before work. Follow the equipment instructions for stored energy and safe isolation.
- Do not bypass grounding, overload protection, monitored safety devices or fire-control functions to make the equipment operate. Diagnose the underlying fault.
- Restore covers and wiring protection, then complete the model-specific functional and safety checks before returning the installation to normal use.
Related Products and Important Differences
- CPS-U monitored photo eyes — separate protection devices for approved commercial-door controls; match the operator and environment.
- TDC12X1BMC MAXUM trolley operator — a complete-operator comparison, not evidence that this legacy service part fits MAXUM.
Frequently Asked Questions
Is this a complete electrical box?
No. The manufacturer identifies it as the Auto Reversal System PCB, a subassembly.
Will it fit every MT generation?
No general fit is established. Match the actual control revision and current service recommendation.
Can it replace required photo eyes?
No. Retain all manufacturer-required protection and approved controls for the installation.
Will a replacement fix a binding door?
No. Correct the mechanical fault and complete the prescribed reversing and protection tests after service.
Need Help Confirming the Right Product?
Contact Garage-DoorParts.com before ordering. Send the full equipment model, readable part labels and photographs of the installed assembly. Include the dimensions, electrical configuration or accessory details relevant to your project so the listing can be checked against the actual installation.
Details
Need Help With Compatibility?
Not sure if this is the correct part for your garage door, operator, gate system, or application? Contact Us before ordering — we’re happy to help.
Garage-DoorParts.com carries a large selection of residential and commercial parts, and many components can look similar while having important differences in dimensions, model numbers, voltage, mounting, or compatibility.
For the best assistance, please provide as much information as possible, including the manufacturer, model number, part number, door or operator type, dimensions, and clear photos of the existing part or equipment.
Our goal is to help you identify the correct product before you order and reduce the possibility of ordering an incompatible part.
Contact Us with your product questions and compatibility information, and we’ll do our best to point you in the right direction.
Shipping & Returns
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We are committed to ensuring a positive shopping experience for all our customers. If for any reason you wish to return an item, we invite you to reach out to our team for assistance, and we will evaluate every return request with care and consideration.