Fujitsu aircon PCB repair in Singapore
A Fujitsu board code says which circuit reported the fault, not whether the board itself has failed. We test the indoor PCB, outdoor PCB and inverter or driver stage separately, explain what failed and quote after diagnosis.
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Signs your Fujitsu aircon needs a PCB check
These symptoms can involve a control board, but they can also come from wiring, a sensor or another part connected to the board.
The unit has power but will not start
Lights or the controller may still respond while the indoor unit, outdoor unit or both refuse to run normally.One room or the whole system stops responding
The pattern across rooms helps separate an indoor-board problem from an outdoor or shared communication fault.A communication or board-related error appears
A Fujitsu code, blinking light or repeated restart gives us a useful starting point, but it still needs electrical testing.
Examples of Fujitsu systems we check
ASAG / ASYG residential wall-mounted systems
AOTG / AOYG multi-split outdoor systems
AUXG ceiling cassette systems, subject to panel and access checks
Model not listed
Send photos of the indoor and outdoor model labels, plus the error code or a short video of the symptom.
A board-related code does not always mean a failed PCB
Before ordering model-specific electronics, we check three problems that can make a healthy board appear faulty.
Power or wiring fault
Loose terminals, a damaged interconnect or unstable supply can produce board and communication errors.Sensor or connected load
A shorted thermistor, motor or valve can pull down a healthy board or make its input look incorrect.Inverter power stage
On inverter systems, the main control PCB and the IPM or driver circuit are tested as separate failure points.
We check the power supply, communication wiring, sensors, connected loads, indoor and outdoor boards, and inverter drive where fitted. How a job runs, from first message to booking.
What is different on Fujitsu systems
A single Fujitsu indoor unit faulting while the other rooms continue normally usually keeps the investigation on that unit's board, sensor or wiring rather than the shared outdoor unit.
Fujitsu error codes related to PCB problems
Open the group that matches where the code appeared on your unit.
Indoor unit or controller57 guides
- 3AIndoor unit communication circuit (wired remote controller) error; Indoor-unit wired-controller communication-circuit error
- 3A.1Indoor-unit wired-controller communication-circuit microcomputer error
- 5UIndoor-unit error
- 11.3Serial forward-transmission error at start-up
- 11.4Serial forward-transmission error during operation
- 12Remote controller communication error
- 16Peripheral device communication error
- 18External communication error
- 18.1External communication 1 error
- 32Indoor unit main PCB error; Indoor-unit main PCB error
- 32.1Indoor-unit PCB model-information error
- 32.6Indoor-unit constant-correction control error
- 33Indoor unit extensions microcomputers error; Indoor-unit motor electricity-consumption detection error
- 33.2Indoor-unit motor electricity-consumption detection microcomputer error
- 35Manual-auto button error
- 35.1Indoor-unit manual-auto switch error
- 37Indoor unit transmission PCB error
- 38Network convertor PCB error
- 39Indoor-unit fan-motor power-supply error
- 39.1Indoor-unit fan-motor 1 power-supply error
- 42Indoor heat-exchanger temperature-sensor error
- 51Indoor-unit fan-motor error
- J5Zone control interface error
- OP 1x / TIMER 1xSerial communication error
- OP 1x / TIMER 2xWired remote controller communication error or server room control communication error; Wired remote controller communication error
- OP 1x / TIMER 5xSerial communication error
- OP 1x / TIMER 6xPeripheral unit transmission PCB connection error
- OP 1x / TIMER 8xExternal communication error
- OP 2x / TIMER 2xIndoor unit capacity error; Indoor unit PCB error
- OP 2x / TIMER 3xCombination error; Indoor unit PCB error
- OP 2x / TIMER 4xConnection unit number error for indoor secondary unit, indoor unit, or branch box; Connection unit number error for indoor secondary unit, indoor unit, or branch unit
- OP 2x / TIMER 6xAddress setting error in wired remote controller system; Indoor unit address setting error
- OP 2x / TIMER 9xIndoor unit PCB error
- OP 3x / TIMER 2xIndoor unit PCB model information error; Indoor unit PCB error
- OP 3x / TIMER 3xIndoor unit PCB error
- OP 3x / TIMER 5xIndoor unit PCB error
- OP 3x / TIMER 9xIndoor unit PCB error
- OP 3x / TIMER 10xIndoor unit communication circuit error for wired remote controller; Indoor unit communication circuit error
- OP 4x / TIMER 2xIndoor unit PCB error
- OP 4x / TIMER 3xIndoor unit PCB error
- OP 5x / TIMER 2xOutdoor unit electronic component error
- OP 5x / TIMER 3xOutdoor unit electronic component error
- OP 6x / TIMER 2xOutdoor unit main PCB model information error or communication error; Outdoor unit electronic component error
- OP 6x / TIMER 3xOutdoor unit electronic component error
- OP 6x / TIMER 4xOutdoor unit electronic component error
- OP 6x / TIMER 5xOutdoor unit electronic component error
- OP 6x / TIMER 10xDisplay PCB microcomputers communication error
- OP 8x / TIMER 2xOutdoor unit electronic component error
- OP 8x / TIMER 3xOutdoor unit electronic component error
- OP 8x / TIMER 4xOutdoor unit electronic component error
- OP 9x / TIMER 4xOutdoor unit electronic component error
- OP 13x / TIMER 2xBranch boxes error [Flexible Multi]; Branch boxes error [flexible multi-split type]
- OP off / TIMER 2xSerial communication error
- OP off / TIMER 3xSerial communication error
- OP off / TIMER 4xSerial communication error
- OP off / TIMER 5xSerial communication error
- OP off / TIMER 8xIndoor unit communication circuit error
Outdoor unit10 guides
- 6AOutdoor unit display PCB error
- 11.1Serial reverse-transmission error at start-up
- 11.2Serial reverse-transmission error during operation
- 13Communication error between Outdoor unit
- 62Outdoor unit main PCB error; Outdoor-unit main PCB error
- 62.1Outdoor-unit PCB model-information error
- 62.2Outdoor-unit PCB microcomputer communication error
- 69Outdoor unit transmission PCB error
- 84Outdoor-unit current-sensor error
- 97Outdoor-unit fan-motor error
Codes can mean different things across model and system families. Every code is in the full lookup for this brand. Last reviewed 2026-08-21.
Is Fujitsu PCB repair worth it?
Parts and timing
Common Fujitsu parts remain available, but older outdoor boards and fan motors can take longer to source than equivalent Daikin or Mitsubishi Electric parts.Our recommendation
PCB repair is usually sensible when the rest of the system is healthy, the exact board revision is available and testing has ruled out wiring, sensors and connected loads. Fujitsu systems commonly have a service life of 10-14 years. For a system over 12 years, sourcing Fujitsu parts for older units gets harder. Major component failures at this age usually favour replacement, especially if the system has had multiple prior repairs.
If replacement makes more sense, we compare the repair quote with a suitable new system. See our aircon system replacement process.
Other Fujitsu repair checks
If testing rules out this part, these are the next checks on the same system.
Workmanship warranty
We stand behind the repair we carry out, and we are straight about the part of the cover we do not set ourselves.
Labour
30-day workmanship warranty. If the same fault returns from our repair, we come back and the labour is on us, with no second diagnostic visit fee.
Parts
Parts carry the distributor's warranty for that component, so the term varies by part. We tell you both terms before you approve the work.
Frequently asked questions about Fujitsu PCB repair in Singapore
What are the signs of a Fujitsu PCB problem?
How do you confirm a Fujitsu PCB fault?
Is a Fujitsu error code enough to order the PCB?
Should I repair or replace my Fujitsu aircon?
We cover all of Singapore. Find aircon services in your area.
Describe your situation
Tell us what’s going on. Symptoms, setup, photos, anything we should know. We’ll assess and come back with the right next step.