aircon pcb board

Faulty Air Conditioner Printed Circuit Board (PCB) Guide

The most expensive part of an AC system is the air conditioner printed circuit board. If the PCB is faulty, it is important to know whether or not it is worth it to repair or replace. We will guide you through what causes the faults in the component and the best ways to make cost-effective decisions regarding whether the faulty PCB should be repaired or replaced.

What Is An Air Conditioner PCB?

PCB is an abbreviation for the term ‘Printed Circuit Board.’ The devices are similar to the CPU or Motherboard of a computer. It is important to realize that a Motherboard is still contained in an air conditioner.

PCB is a green board that acts as the wiring for different components such as transistors, capacitors, resistors, etc. There are connections between the various components called conductive tracks. They are made with a layer of copper and masked with a fibreglass silkscreen.

A PCB’s main function is designed to include different components to perform data communication, a specific command, or calculate the output for controlling the AC.

What Causes An AC’s PCB To Become Damaged?

PCB circuits are highly sensitive to electrostatic discharge (ESD) and various elements. It is very important to be aware that even small ESD discharges can damage the PCB’s components. The following are some of the most common reasons why AC PCBs become damaged.

  • Improper input voltage in the AC’s PCB while a technician is installing it.
  • Short circuit – This is the most common cause by far of PCB damage.
  • Cockroaches, ants, and other small insects are widely known that cockroaches and other insects like warm places. Therefore, they often hide in electronic and electrical devices that produce heat. That is why whenever a cockroach gets inside the circuit board, it will most likely cause damage via short circuits, create static charges, and other problems.
  • Exposure to various elements. Dust, moisture, and heat exposure are common causes of PCB damage.
  • Accidental impact – This involves accidents such as dropping it during the cleaning process.
  • Another common factor is age – Everything in the world has an age limit. Most PCB components, unfortunately, have limited age limits.

Can a PCB Be Repaired?

Fortunately, it is possible to repair a PCB. However, the task demands correctly diagnosing the problem, repairing tools, and technical knowledge.

However, specific circuits must be repaired within a workshop environment and cannot be fixed on-site. After repairs are completed, a test needs to be conducted to ensure the PCB is functioning correctly.

Why Should A PCB Be Replaced Instead of Repaired?

It is always smart to replace a faulty PCB instead of trying to repair it. That is because the repair process might take longer and a skilled technician’s services are required, which could end up being quite expensive for you. Technicians and experts recommend repairs only if all else fails and as the last result or if the AC’s PCB has been discontinued. Another thing to keep in mind is that repairs always have an error aspect to them. As a result, there is always a high possibility of errors when repairs are involved.

How Much Does It Cost to Replace AC Circuit Boards?

The price to replace a failed PCB is going to depend on several different factors, including the year, brand, and model of your AC unit. Therefore, on a newer air conditioner model, it will cost around $500 (depending on the factors just mentioned). Since this is not cheap, it can be beneficial to consider getting a used PCB, particularly for a newer AC model.

The new PCB for the Mitsubishi Mxy-3a28va, for example, will cost you around $600. However, a second-hand model will only cost around $300. You can save $300 with this option.


Ultimately, there is no single right answer when it comes to whether your PCB should be replaced or repaired. It will depend on how significant the damage is and the amount of work necessary to successfully repair it.

However, if the AC circuit board is sufficiently faulty that replacement appears to be a worthwhile option to explore, then give a call today for assistance!