Circuit Board Repair and Maintenance Guide

PCBA boards are considered one of the main components of electronics, as they help to operate electronics. However, over time or due to human error, various unexpected failures may occur on the circuit board, causing the equipment to malfunction. To address this issue, FS Technology has provided a detailed guide for circuit board repair and maintenance in this article to help protect your circuit. Some common PCB faults are listed below, and if you want to learn more, you can read our blog post “A Collection of Common PCB Problems”.

Corrosion
Overheat
Scratches
Short Circuit
Component Failure

Step 1: Prepare Repair Tools

When PCB boards fail, many people choose to repair them rather than order new ones, but this process can be dangerous and complicated. Before beginning any repair work, it is essential to verify that you have the necessary experience and proper training to perform the task safely. Failure to meet these conditions may result in injury. For safety reasons, FS Technology recommends that you purchase PCB repair services under the guidance of professionals. You should prepare the following repair tools in advance:

Soldering iron, welding torch, or hot air gun: Although these tools are used for heating, their purpose, application field, and usage method may differ. Therefore, you should prepare them according to the specific situation.
Desoldering tool: This tool is necessary for removing old solder or desoldering components on the circuit board.
Multimeter: A multimeter is used to measure the voltage, current, and resistance of the circuit, which is helpful in finding faults on the single board.
Wire cutters and wire strippers: These tools are used for repairing and stripping wires when repairing boards.
Other materials: Copper foil, cotton swabs, and rubbing alcohol are some additional materials that may be needed.

Step 2: Officially Start to Repair PCB

Confirm the point of failure

When a PCB fails, it is difficult to determine where the problem is direct. The issue may arise in components, traces, via, or other locations. The most efficient approach is to locate the fault point first and then implement rescue measures. In the PCB production process, PCBA companies identify the issue’s location through a series of testing methods, such as AOI, X-Ray, etc. However, electronic enthusiasts may not be able to afford the high cost of purchasing professional equipment. In this case, performing a physical inspection through manual visual inspection, multimeter, and other testing methods is an effective measure. Combining the test results with FS Technology’s PCBA failure analysis can help you understand the problem and start saving your circuit boards.

Remove faulty part

During the repair process, we use heating and desoldering tools, which can be challenging and may cause secondary damage if not handled with care. It is important to keep the tools away from adjacent correct components as much as possible. To help with this, FS Technology provides the following tips:

Hold the heating tool close to the faulty component (within 6 inches) and pay attention to the distance from other components.
Control the heating time and stop heating after a few seconds. Lift the component with tweezers or other tools. If you find it difficult to pick up the component during this process, reheat it and do not use brute force. Note: Due to the high temperature, this process must rely on external force instead of direct hands.
If the mat is damaged due to heating, it is best to use a sharp tool to peel it off.
When fixing a broken PCB, the focus should be on removing the faulty part with the least possible impact.

Clean tracks to remove solder

Once the broken pad has been removed, the remaining solder must also be removed. FS Technology recommends the following methods:

Use a knife or other sharp tool to scrape off the residual solder. Be careful not to damage the PCB traces.
Achieve removal by gently rubbing the board surface with very fine grit sandpaper.
Use a solder suction device with a heat gun. After the heat gun melts the solder joints, aim the suction nozzle at the residual solder to suction it out.

Put the copper tape on the track

After completing the above steps and cleaning the board surface, place the prepared copper tape on the target area. Remember that the copper tape should be positioned to overlap with the existing trace and cover part of the existing through-hole and its surrounding area. Once completed, double-check the work done in the process.

Welded joint

When connecting the copper tape to the repair area on the PCB, it’s important to pay close attention to the solder joints. There are two solder joints that require special attention:

The high heat from soldering can quickly melt the copper tape, so it’s essential to be precise when soldering.
Adjust the temperature of the soldering iron to slow down the melting time, and work deliberately to prevent mistakes and ensure accuracy.

Recovery via

To ensure that the copper tape adheres firmly to the entire pad area, it is recommended to use a hard tool with a round tip, such as a pen. After soldering, press down on the area and rub it firmly. The adhesive should still be tacky after applying heat.

This technique allows you to locate the via and pierce it with a paper clip or similar tool. This step is important to ensure that the via is not covered by the copper tape and that the electrical connection is maintained.

Welded components

At this stage, the printed circuit board has been repaired, and it is time to reassemble the PCB by installing new components in their designated positions. It is important to note that the new joint formed between the freshly applied copper tape/pad and the track is fragile. Therefore, it is crucial to ensure that the new component is connected precisely in the designated place, and controlled heat should be applied to melt the solder.

Beautify the repaired area

The finished patched PCB may not look aesthetically pleasing, and if you’re a perfectionist, you can use scissors or a utility knife to carefully cut the adhesive copper tape to size and make it look neater. However, it’s important to note that although the newly repaired PCB has regained its function, it may not be as sturdy as the original PCBA board, so handle it with care when using it.

Step 3: Routine PCB Maintenance

To minimize the risk of board failure and extend the life of your PCB, regular maintenance is essential. FS Technology recommends the following maintenance tips:

Storage

When dealing with high volume PCB assembly, storage can be a concern. Proper storage conditions are critical to prevent board failure. Here are some storage conditions that FS Technology recommends for PCBs:

The storage area should be dry and well-ventilated. High humidity can cause moisture to build up on the board and corrode the surface. Consider adding an exhaust fan to the storage area to keep the air dry.
Avoid exposing the board to direct sunlight or other light sources for extended periods of time, as this can lead to board damage.
Protect the PCBA board with sealed packaging. FS Technology typically uses anti-static bags or foam plastics to prevent component breakdown due to static electricity.

Periodic inspection

Check the contact performance of components to ensure they are properly installed on the board and firmly secured.
Inspect solder joints to ensure they are not loose or cracked.
Examine the board surface, particularly the edges and contact areas, for any signs of damage or corrosion.
Clean the PCB to remove any dirt and dust that may affect performance.
Conduct electrical testing to ensure that the board’s electrical performance is optimal.

Timely replacement of bad components

Broken components can have a ripple effect on other good parts of the board if they are not repaired in a timely manner. For example, a faulty component may cause the circuit board to overheat and damage the panel or other good components. In more serious cases, the entire electronic device may become damaged or fail. Therefore, it is important not to delay and to repair the circuit board as soon as possible to prevent further damage or failure.

IMPORTANT: PCB Fix Safety Concerns

Make sure to turn off the power supply of the circuit board before starting any maintenance, not only for the safety of the board but also for your personal safety.
Be sure to use appropriate protective equipment to protect yourself from electrostatic discharge or chemical hazards. Common protective equipment includes anti-static wrist straps, safety glasses, masks, and gloves.
Use proper tools for circuit board repairs, including decoding and soldering tools.
Perform repairs in a well-ventilated area to avoid inhaling toxic fumes from soldering and desoldering.
Protect circuit boards from ESD by using an anti-static work surface.
Follow the repair guidelines mentioned above to minimize any pressure or stress on the circuit board that could cause secondary damage.
Store unused circuit boards properly in a protected place, and use an anti-static bag for additional protection.
Dispose of any waste in accordance with local environmental regulations to avoid any negative impact on the environment.

FAQ

Wouldn't it be more cost-effective to buy a new one?

For some common PCBs, people may think that buying new ones is more efficient and of higher quality, but for industrial control PCBs, this approach is clearly not advisable. Industrial control boards are typically expensive.

Can it be done without repair tech?

Neither against nor recommended.

It can be both beneficial and risky to repair circuit boards yourself. It is recommended to take a detailed course or undergo necessary training before starting to acquire the skill. However, it is not recommended nor discouraged.

Do you provide repair services?

We apologize that we do not offer repair services. As a PCBA company based in China, we specialize in providing a wide range of manufacturing and assembly services. However, if any malfunctions occur during our work, we are capable of addressing and repairing them as part of our service commitment.

How can the FS team help you?

In addition to offering a wide range of manufacturing and assembly services, our blog provides extensive knowledge on topics such as PCB repair tutorials, DIY PCBA boards, and basic knowledge sections.

Moreover, we strive to engage with our customers more, and we welcome our customers to contribute as authors to our blog. This allows customers to receive technical support free of charge.