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Have you ever experienced sudden interruptions, short circuits or burnouts in your electronics? PCBs are essential for powering electronic devices, but they can fail. It’s more economical and convenient to repair them than replace them.
In this, we’ll introduce common PCB failures, the tools and especilly steps required for PCB repair, and some troubleshooting tips. Choose ELE PCB and let us be your source of knowledge and reliable partner in the field of printed circuit boards.
In this PCB repair guide
What is PCB Repair and Why Do it
PCB board repair is the process of identifying, repairing, or swapping out broken printed circuit board components or circuits. Fixing PCB can involve everything from repairing damaged traces to replacing burned-out pads.
Repairing PCBs not only reduces e-waste pollution and costs, it is also an essential skill for electronics enthusiasts and engineers, and successfully repairing a faulty circuit board is extremely satisfying.
Common PCB Failure
The following are common types of PCB failure:
| Types | Examples | Possible Reasons |
| Physical Damage | Cracking or bending | excessive mechanical or physical stress |
| Broken solder joints | temperature difference in components thermal coefficient of PCB | |
| Electrical Failure | Short circuit | invisible solder bridges, humidity |
| Open circuit | loose solder joints, wire breaks | |
| Burnout of components | over current, high voltage | |
| Component Problems | Component misalignment | components move or shift |
What Do You Need Before Fixing PCBs?
1. Necessary Preparation for Safety
Keep safety in mind when repairing PCB boards and try to follow these steps to work safely and efficiently.
- Discharge all electronic equipment: Make sure all capacitors are discharged before starting to prevent electrocution.
- Wear safety glasses and gloves: It is important to protect your eyes and hands as solder or other debris may be splashed during the repair process.
- Wear antistatic clothes: The sudden flow of sparks across two surfaces is called electrostatic discharge(ESD). Anti-static clothing to allow the excess charge to be released.
- Keep your hands and circuit boards clean: You need to wash your hands to ensure there’s nothing negative to affect your boards.
2. Repair PCB Kit
You can make your choice of repair tools based on your own level and the difficulty of acquiring them, but there are a few must-have tools：
Soldering iron: Your primary tool for taking and reassembling components. For better control, get one with a temperature adjustment feature.
Desoldering pump or solder wick: Helps you remove old or unwanted solder when removing defective parts.
Multimeter: The essential tool for component testing, short circuit detection, and confirming the success of the repair.
Solder wire: To create neat, stable junctions, use high-quality solder and flux.
Tweezers, wire cutters, and magnifying glass: Some practical instruments to help you handle the components, cut leads and so on.
If your ability is advanced, you can try these tools to help you repair more complex boards: Hot air rework station, UV solder mask pen, fume extractor, etc.
The Steps of Repairing Circuit Boards
When everything is ready, you can start repairing. ELE PCB will show you an understandable, step-by-step guide to PCB repair, including PCB troubleshooting and repairing tips.
Step 1: Inspection of Appearance
Step 2: Static Measurement
The first step when receiving a faulty circuit board is to carry out a visual inspection of its surface condition. Check for obvious damage such as:
- bulging (e.g. raised tops on electrolytic capacitors)
- cracking (e.g. fractures in resistor or chip casings)
- scorching (e.g. black burn marks on components or the PCB itself)
- leakage (e.g. brown liquid around electrolytic capacitor leads)
These obvious faults often indicate the core issue, and replacing the corresponding component will usually resolve the problem.
Take a static measurement of the parts on the board using a multimeter. Check if there is a blown fuse, if there is a shorted-off or removed capacitor, if there is normal diode behavior.
- Set the multimeter to continuity test mode. Touch the red and black probes to the pins of the circuit or component under test. If the buzzer sounds continuously and the display reads ‘0 Ω’, there is a short circuit present.
- Trace the copper trace and inspect nearby components for issues such as diode breakdown or capacitor shorting. If the display reads ‘OL’ (infinity), then an open circuit exists. Check solder joints, wires and the component itself for breaks.
- For integrated circuits, measure the resistance between their pins and check for a short or open circuit.
Step 3: Replace the Broken Components
In case of broken parts, utilize a hot air gun or a soldering iron to loosen the components from the PCB and afterward replace them with new ones. During soldering, observe solder time and temperature to avoid causing damage to the PCB and new components.
Pay attention: If repairing with through-hole components, be sure to desolder all pins. Once the solder is melted, we can use tweezers to gently lift the part to avoid subsequent electronic circuit board repairs.
Step 4:
Repairing PCB Traces
If you notice that traces of copper foil on the PCB is burnt or short-circuited, you can solder it using copper foil tape or wire. First, you need to scrape the solder mask away, and then use a solder jumper wire to fix it.
Faced with burnt PCB traces, connect both sides of the break point in copper foil tape or wire; repair short-circuited traces, remove the short-circuited copper foil or wire using sharp-nosed tweezers or pliers and then reconnect.
Step 5:
Testing and Verification
Functional test: After repairing, re-energize the PCB and carry out a functional test to check whether the device returns to normal operation and whether the fault phenomenon has disappeared. If the device is still faulty, one must revisit the repair process and identify where the problem lies and correct it.
Stability test: Test the long-term stability of the PCB to see if the device will exhibit any abnormal states while running, like heat, crash, restart, etc. If the device is stable during the stability test, it means successful repair.
Troubleshooting Tips for You
The hardest part is not operating the repair but finding the cause of the failure, which is especially difficult for beginners. Here are some troubleshooting tips for you.
Removal One by One
Test, repair, and replace parts as needed until the problem is fixed. Ensure everything is working by replacing missing parts.
This approach is not too complex for most repairers, though mistakes can still be made. Some circuit boards with data chips cannot use this method.
Compare with Good
One of the most commonly used methods for fixing circuit boards without drawings is the comparison method. The goal of fault detection is accomplished by comparing the curves of the nodes of the two boards to identify any anomalies.
Check Normal Working State
The technique checks each component’s normal working state. If it deviates, the device or its parts malfunction. This method requires theoretical knowledge and practical experience.
Principle Analysis
This method is to analyze a board’s working principle. For example, engineers can understand the schematic diagram of relatively easy repairs without the requirement for drawings for some boards, like switching power supplies.
ELE PCB presents a comprehensive overview of the complete PCB repair process, from physical damage restoration to circuit short-circuit debugging, along with a list of professional tools and step-by-step instructions. We provide reliable quality control and stability testing to help you extend the life of your equipment. As a top supplier, we combine efficient technology with tailored services to help you enhance product quality and eliminate errors.
Contact us now for one-stop PCB manufacturing!
FAQs
A1: The types of failure:
| Types | Physical Damage | Electrical Failure | Component Problems | Other Failure |
| Examples | Cracking or bending | Short circuit | Component misalignment | Corrosion |
| Broken solder joints | Open circuit | Electronic component warranty expiration | Design Failure | |
| Burnout of components |
A2:
Yes. There are some steps for repairing burnt PCB:
- Repairing a small burn-through in the surface:
- Gently sand the affected area using fine sandpaper or a sanding tool until the copper is exposed.
- Use silver paint or conductive ink to repair the area. Then fix with a soldering iron or heat gun.
- Repairing a major burn-through in copper foil:
- Trim the copper foil as necessary.
- Use a conductive adhesive to stick the foil to the burned-through area of the copper.
A3:
Yes. You can fix cracked PCB by using
some PCB-specific, high-temperature-resistant glue or tape for bonding.
some PCB-specific, high-temperature-resistant glue or tape for bonding.
A4:
The cost of circuit board repair is not fixed, but rather depends on the complexity of the board, the amount of damage, and the cost of materials and labor required to complete the repair. In general, a simple circuit board repair may cost a few dozen dollars, whereas an advanced circuit board repair may cost hundreds or even thousands.
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