What Is the EBR78940610 LG Refrigerator Main Control Board Replacement?
The EBR78940610 is the genuine OEM main control board for LG refrigerators, mounted on a bracket behind an access panel on the lower back of the cabinet. It manages compressor and fan operation, temperature regulation, and the defrost cycle that keeps the fridge and freezer sections running correctly. This replacement control board restores those functions when the original fails. FailSafe Certified and backed by a 1-year warranty from Appliance Pro USA.
EBR78940610 was a production update of this board and was later succeeded by EBR78940612 - both are the same control board at different points in the production run. If your unit's sticker reads EBR78940612 instead, that board is the correct match for your refrigerator.
What Does the EBR78940610 Fix on a LG Refrigerator?
If your refrigerator is doing any of the following, the main control board is a common cause:
- Refrigerator not cooling, or running too cold
- Control panel is frozen or won't respond to input
- Unit shuts off intermittently or loses power on its own
- Display is showing an error code
- Compressor or fans won't kick on
- Heavy frost buildup because the defrost cycle isn't completing
These symptoms point to the refrigerator control board as the most likely cause - but appliances are complex systems, and the same symptoms can occasionally stem from a sensor, switch, wiring harness, or motor issue. If a technician has identified the control board, or you've ruled out those components yourself, this board is your fix. When in doubt, contact us before you order - we're happy to walk you through some troubleshooting, and a photo of your board is usually all we need. A diagnosis from a local appliance technician works too.
How Do I Know If This Is the Right Board for My Refrigerator?
Pull the refrigerator out, unplug it, and remove the lower rear access panel to find the board and its sticker. Match the number on that sticker to what you're ordering rather than going off the model number alone. EBR78940610 and EBR78940612 both refer to this same board. Your LG refrigerator part number is on the sticker on the original board - look for the EBR or CSP prefix.
Other part numbers used for this board: EBR78940612. Retailers and parts catalogs list the same board under these numbers.
Not sure? Send us a photo of your board and its sticker before you order and we'll verify it for free - same business day.
Compatible Refrigerator Models
This board is ordered by part number, not by appliance model. Send us your full model number and a photo of your board's sticker and we will confirm fitment before you buy - same business day.
This model list is for reference only. LG may change boards between production runs, so two appliances with the same model number can use different boards. Always order by the part number printed on your original board - it is the only identifier that decides.
Genuine OEM - FailSafe Certified™ Reconditioned
Every EBR78940610 board from Appliance Pro USA is a genuine OEM LG board restored to reliable working condition through the FailSafe Precision Protocol™, our 4-step recertification process built around what actually fails on this board:
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Failure Pattern Analysis - We've mapped the failure signatures specific to this board, identifying which components degrade and fail over time.
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Targeted Component Replacement - The components this board is known to lose are replaced before they get the chance to fail.
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Proactive Rebuild Standard - Known high-failure components are replaced with new parts on every board, regardless of whether they show a problem yet. Degraded parts don't ship.
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Final Certification - Every board is tested and certified to our internal FailSafe Precision Protocol standard for function and lifespan before it ships.
Key Features
- Genuine OEM LG main control board - not an aftermarket copy
- FailSafe Certified before it ships
- Direct fit replacement, no soldering or modification needed
- Minor cosmetic wear may be present due to prior installation - it does not affect performance
Board Type and Function
This is the brain of the refrigerator's cooling system. It reads input from the temperature sensors and tells the compressor and fans when to run, manages the defrost heater on a schedule, and shifts between cooling modes to keep both compartments at the right temperature. When it fails, the refrigerator can lose cooling control entirely, get stuck running constantly, or stop responding to the display altogether.
Common LG Refrigerator Error Codes
If your LG refrigerator is displaying an error code, the table below describes what it typically indicates. Codes marked ★ are most directly associated with main control board failure. These are general LG codes and can vary by your exact model. Always confirm the exact meaning in your model's owner's manual or service guide before ordering any part.
| Code |
What It Means |
| ★ CO |
Communication failure between main control board and display board |
| ★ Er CF / CF |
Condenser fan feedback signal error - board not receiving fan confirmation signal |
| ★ 22 |
Compressor relay problem - board-managed compressor circuit fault |
| ★ dH |
Defrost cycle timed out - evaporator did not reach target temperature within 1 hour |
| Er FF |
Freezer evaporator fan failure - fan not circulating cold air in freezer |
| Er rF |
Refrigerator evaporator fan failure - fan not circulating air on fresh food side |
| Er FS |
Freezer temperature sensor failure |
| Er rS / r2 |
Refrigerator temperature sensor failure - upper (rS) or lower (r2) section |
| dS |
Defrost temperature sensor short or disconnection |
| Er IF / IS / It |
Ice maker fan (IF), temperature sensor (IS), or motor (It) failure |
| CH E / CL E |
Refrigerant leak detected - high-side (CH E) or low-side (CL E). Requires professional service |
| OF F |
Demo mode active - cooling disabled. Not an error. Deactivate via control panel hold sequence |
Error code definitions vary by LG model series. Always confirm the exact meaning in your refrigerator's owner's manual or service guide before purchasing any part.
★ = Most directly associated with main control board failure
How to Install a LG Refrigerator Main Control Board
Shut off power at the breaker or unplug the unit before you start. Remove the screws holding the lower rear access panel and set it aside to expose the board. Take a photo of the wiring harness before you disconnect anything, then release each connector's locking tab with a flathead screwdriver and pull it free. Handle the new board by its edges, seat it in the mounting clips, and reconnect each harness exactly where it came from. Reinstall the access panel, restore power, and most people are done in under 30 minutes with basic hand tools. Give the refrigerator a few hours to settle into its temperature cycle before you judge whether the repair worked.
Shipping
Every board is physically in stock - no backorders, no drop shipping. Orders placed before 4:00 PM EST ship the same business day. Tracking provided on every order.
Warranty
Backed by a 1-year warranty from Appliance Pro USA (registration required - the card is in the box). If the board fails due to a defect within the warranty period, we'll repair or replace it at no charge (shipping fees may apply). Warranty coverage is determined at Appliance Pro USA's discretion. Boards that have been tampered with, or with the verification seal (hologram or tamper-evident sticker) removed or damaged, are not eligible for warranty coverage. Damage caused by improper installation, electrical surges, or physical damage is not covered.
Returns
Returns are accepted within 30 days of delivery. Boards that are unopened and uninstalled, in original condition with the verification seal (hologram or tamper-evident sticker) intact, qualify for a full refund. If the board has been opened or installed, contact us before sending it back with a photo of the board you received, the reason for the return, and a photo of your original board's part-number label so we can verify fitment and approve the return. Boards returned used, altered, damaged, or with the verification seal missing may receive a partial refund in line with our return policy. Exchanges for the correct part are always available.
Not sure it's the board? Before you order, and before you return, contact us. We offer free troubleshooting help and can usually tell from a photo of your board and its symptoms whether this is the right part. Only a technician can fully diagnose your appliance.
