What Does Error Code 1AC Mean on a Samsung Washing Machine?
Power off the washing machine at the wall socket, wait 60 seconds, then switch it back on and restart the cycle — a simple reset clears the fault in many cases where the error was triggered by a temporary signal dropout (takes about 2 minutes).
Fault description
Error code 1AC points to a breakdown in communication between two of the most important circuit boards inside your Samsung washing machine — the main PCB and the sub PCB. These two boards work together constantly to coordinate every stage of a wash cycle, and they talk to each other through a solenoid connector. When that connection is interrupted or lost, the machine detects the fault and stops to protect itself.
When 1AC appears, the machine will typically halt mid-cycle or refuse to start at all. You may notice the display freezing, buttons becoming unresponsive, or the drum simply not moving despite the machine appearing to be powered on. The fault is electronic rather than mechanical, so there are usually no unusual noises or leaks accompanying it.
The good news is that this error is sometimes caused by nothing more than a loose connector or a temporary signal glitch, both of which can be resolved without specialist tools.
Causes
- Temporary signal dropout or software glitch — A brief power fluctuation or software hiccup can cause the two PCBs to lose sync momentarily. This is the most common trigger and is usually resolved by a full power cycle.
- Loose or unseated solenoid connector — The solenoid connector linking the sub PCB to the main PCB can work itself loose over time due to vibration during spin cycles. Even a slightly unseated connector is enough to break the communication signal.
- Damaged or corroded wiring harness — The wiring harness that runs between the two boards can suffer from wear, pinching, or moisture-related corrosion. A damaged wire in this harness will interrupt the data signal even if the connector itself appears secure.
- Faulty sub PCB — If the sub PCB has developed an internal fault — due to a power surge, component failure, or age — it may no longer be able to send or receive signals correctly. In this case, the board itself will need to be replaced.
- Faulty main PCB — Less commonly, the main PCB is the source of the problem. If it cannot interpret signals from the sub PCB, the communication error will still be logged even if all connectors and wiring are intact.
Step-by-Step Fix
- 1
Power cycle the machine
Switch the washing machine off at the wall socket and unplug it completely. Leave it unplugged for at least 60 seconds to allow the control boards to fully discharge, then plug back in and power on. Attempt to start a new cycle and check whether the 1AC code returns.
- 2
Check the door and drum for obstructions
Before opening any panels, make sure the door is fully closed and latched, and that no laundry is caught in the door seal. An incomplete door closure can sometimes cause the sub PCB to register a fault state. Remove any obstruction and try again.
- 3
Access and inspect the solenoid connector
Disconnect the machine from the mains supply before proceeding. Remove the top panel of the machine (usually secured by two or three screws at the rear) to gain access to the PCB area. Locate the solenoid connector between the main and sub PCBs — it is typically a small multi-pin plug — and press it firmly until you feel or hear it click into place.
- 4
Inspect the wiring harness between the two boards
With the top panel removed, trace the wiring harness that connects the sub PCB to the main PCB. Look for any wires that appear pinched, frayed, burnt, or corroded at the terminals. If you find a damaged section, the harness will need to be replaced rather than repaired with tape.
- 5
Reseat all connectors on both PCBs
While you have access to the boards, gently press each connector on both the main and sub PCBs to ensure none have worked loose. Vibration over time can cause multiple connectors to shift slightly. Do not force any connector — if it does not seat easily, check you have the correct orientation.
- 6
Reassemble and run a test cycle
Replace the top panel, reconnect the machine to the mains, and run a short test cycle such as a quick wash or rinse-and-spin. Monitor the display throughout. If the 1AC code does not reappear, the fault has been resolved. If it returns immediately, the issue is likely a faulty PCB.
Affected models
Select your model to see its full troubleshooting page.
When to call a service technician
If the 1AC error code returns immediately after every reset attempt, and you have already reseated the solenoid connector and inspected the wiring harness without finding any obvious damage, the fault is most likely an internal failure of either the sub PCB or the main PCB. Diagnosing which board is at fault requires specialist test equipment, and replacing a PCB involves handling components that can be damaged by static electricity if not handled correctly.
You should also contact a service technician if you notice any signs of burning, melted plastic, or a burning smell near the PCB area, or if the machine has recently been exposed to a power surge. These situations go beyond straightforward connector checks and require professional assessment.
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Frequently Asked Questions
Can I keep using my Samsung washing machine while it shows error code 1AC?
No. When the 1AC error is active, the machine will not complete a cycle and may not start at all. Attempting to force it to run while the PCB communication is broken could cause further damage to the control boards. It is best to resolve the fault before using the machine again.
Will a factory reset fix the 1AC error code?
A factory reset can clear the error if it was caused by a temporary software glitch, but it will not fix a physical problem such as a loose connector or a damaged wiring harness. Try a standard power cycle first — unplug for 60 seconds — before attempting a full reset, as the result is usually the same for this type of fault.
How much does it cost to replace a Samsung washing machine PCB?
The cost of a Samsung sub PCB or main PCB varies depending on the model, but parts typically range from £40 to £150 each. Labour charges from a service technician will add to this. It is worth getting a quote before committing to a repair, particularly on older machines.
Is error code 1AC covered under Samsung's warranty?
If your machine is within its standard manufacturer warranty period, a PCB communication fault would normally be covered provided the damage was not caused by misuse or an external power surge. Contact Samsung support directly with your model number and proof of purchase to check your eligibility before arranging any paid repair.
How do I find the right sub PCB for my Samsung washing machine model?
The full model number is printed on a sticker inside the door frame or on the back of the machine. Use this number — not just the series name — when searching for a replacement part, as PCBs are often model-specific and an incorrect board will not work. Cross-reference the part number on the existing board if possible before ordering.