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PCB Problems

PCB Problems: What Happens When Your Air Conditioner’s Circuit Board Fails

The Printed Circuit Board (PCB) is the brain of your air conditioning system. It controls communication between internal components, manages temperature settings, powers the compressor and fan, and ensures safety features are functioning correctly.

When the PCB becomes damaged, faulty, or fails completely, your entire system can shut down. You may notice your AC not working, controller blinking, aircon error codes, or even your air conditioner not turning on.

At Vital Air Conditioning Services, we diagnose, repair, and replace PCBs across Sydney. Whether it is a minor fault or a complete breakdown, our experienced technicians can get your system back up and running quickly and affordably.

Vital Air Conditioning Services | PCB Problems
Vital Air Conditioning Services | PCB Problems

What Is a PCB in an Air Conditioner?

The PCB is an electronic control board found in both indoor and outdoor units of split or ducted air conditioning systems. It is responsible for:

  • Receiving signals from the thermostat or controller
  • Switching the compressor, fan motors, and reversing valve on and off
  • Regulating system voltage and communication between components
  • Storing and displaying aircon error codes
  • Protecting the system from overheating, electrical surges, and unsafe pressure levels

When the PCB malfunctions, you may see signs like air conditioner not cooling, air conditioner not heating, or AC blowing hot air on cold setting.

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Signs Your Air Conditioner’s PCB May Be Faulty

A faulty or failing PCB can trigger a range of symptoms. These include:

  • Air conditioner not turning on or starting and shutting off unexpectedly
  • AC not working even though the remote and power supply are fine
  • Controller blinking or displaying strange symbols
  • Aircon error codes appearing without explanation
  • Aircon blowing the breaker or aircon tripping electric unit
  • AC freezing up or air conditioner leaking water from irregular operation cycles
  • Fans or compressor running at incorrect times or not at all
  • AC making strange noises such as clicking or buzzing when idle
  • Aircon with no air or weak airflow AC caused by control signal failure

Because the PCB controls all other components, a fault here can mimic symptoms of fan, motor, or thermostat failure.

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Common Causes of PCB Problems

There are several reasons why a PCB may malfunction in your air conditioning unit:

1. Power Surges and Voltage Spikes

Lightning strikes, poor wiring, or unstable power supply can fry sensitive electronic components on the PCB. This is a common reason for aircon tripping the electric unit.

2. Moisture Ingress

Condensation or water leaking into the PCB compartment can cause short circuits. This often results in controller blinking, random shutdowns, or aircon leaking water.

3. Dust and Corrosion

Build-up of dust, insects, or corrosion over time can damage PCB connections, leading to miscommunication between parts and AC not working efficiently.

4. Overheating

Blocked airflow or a failed fan can cause the PCB to overheat, especially in older systems. This can produce aircon error codes or cause the unit to shut off as a safety precaution.

5. Age and Wear

Like all electronics, PCBs degrade over time. Capacitors and solder joints can fail after years of use, often resulting in air conditioner not cooling or starting inconsistently.

How We Diagnose and Repair PCB Issues

At Vital Air Conditioning Services, we provide expert air conditioner repair and PCB replacement services. Here’s how we approach the issue:

1

Full System Diagnosis

We begin by testing the system for aircon error codes, power supply issues, and communication failures between the indoor and outdoor units.
2

Visual and Electronic Testing

Our technicians open the PCB housing to check for burn marks, corrosion, or failed components. We use specialised tools to test capacitors, diodes, and voltage flow.
3

PCB Repair or Replacement

If the board can be repaired safely, we’ll replace damaged parts. In most modern systems, however, full PCB replacement is more efficient and reliable.
4

System Reset and Testing

After installation, we reset your system, clear any stored aircon error codes, and run performance checks. This includes airflow tests, temperature checks, and ensuring there are no controller blinking alerts or communication issues.

Why You Should Act Quickly on PCB Problems

Because the PCB controls the entire system, delays in repair can lead to further damage. For example:

  • The compressor may overwork, leading to a costly breakdown
  • Your fan motor may stop running, causing the AC to freeze up
  • The system may overheat or short cycle, leading to aircon blowing hot air in summer
  • Your energy bills may spike due to inefficient operation
  • The system may stop responding altogether, requiring emergency air conditioner repair

Booking a qualified AC technician near you ensures the issue is addressed before it escalates.

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Vital Air Conditioning Services | PCB Problems

Frequently Asked Questions

Why is my air conditioner not turning on, but there is power?

This often indicates a PCB fault, especially if the controller is blinking or you can hear clicking sounds from the unit.

What does it mean when the controller is blinking and the AC is not working?

It usually signals an aircon error code. The blinking light often points to a failed component, and in many cases, the PCB is the cause.

Can a faulty PCB cause the aircon to trip the power?

Yes. A damaged PCB can send incorrect signals or overload the system, leading to the aircon blowing the breaker or tripping the electric unit.

Why is my air conditioner blowing hot air on a cold setting?

If the PCB fails to activate the cooling cycle properly, it may result in the AC blowing hot air on cold setting or aircon blowing hot air in summer.

Should I repair or replace the PCB?

In most cases, replacing the PCB is more reliable and time-efficient, especially if the system is newer. Repairs are possible in older units but may not offer long-term reliability.

Can PCB failure cause weak airflow or no air at all?

Yes. If the board fails to send the correct signals to the fan motor, it may result in weak airflow AC or aircon with no air from the vents.

Book Your PCB Repair with Vital Air Conditioning Services

If your AC is not working, showing aircon error codes, or your controller is blinking, it could be a sign of PCB failure. At Vital Air Conditioning Services, we offer fast, professional air conditioner repair, including full PCB diagnostics and replacement.

We also provide routine aircon maintenance, full system servicing, and emergency air con repair when you need it most.

Looking for an aircon service near me or an affordable AC repairer in Sydney? Contact our expert team today and restore your system’s brain — the PCB — back to full function.

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Vital Air Conditioning Services | PCB Problems

Discuss your Air Conditioning Needs With Us

Vital Air Conditioning is ready to help you with your cooling or heating requirements. Contact us today for more information on any of the services we provide.

Phone

(02) 9730 0529 (02) 8763 0983

Email

[email protected]

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