Yes, most PC boards can be repaired. A printed circuit board (PCB) usually fails because one or two components have broken down, a solder joint has cracked or a track has burnt through, not because the whole board is beyond saving. With the right diagnostic equipment, a technician can find the failed part, replace it and test the board, often for far less than the cost of a new one. This article explains which PCB faults can be fixed, which usually can’t, what causes boards to fail and how to decide between repair and replacement.
What is a PC board?
A PC board, or printed circuit board, is the flat board that holds and connects the electronic components inside a device. Copper tracks carry signals and power between components such as capacitors, resistors, diodes, transistors, integrated circuits (ICs) and connectors. In industrial equipment you will find PCBs in variable speed drives, servo drives, PLCs and I/O cards, HMIs, power supplies and dedicated machine controllers.
Which PCB faults can be repaired?
| Fault | Typical symptoms | Usually repairable? |
|---|---|---|
| Failed components (capacitors, diodes, MOSFETs, IGBTs, regulators) | No power, tripping, erratic behaviour, visible bulging or burning | Yes – the component is removed and replaced |
| Cracked or dry solder joints | Intermittent faults, especially with heat or vibration | Yes – joints are reworked |
| Burnt or broken tracks | Dead sections of the circuit, scorch marks | Often – tracks are rebuilt with jumper wire or copper repair |
| Corrosion and contamination | Leakage, short circuits, random faults after moisture or dust exposure | Often – cleaned, damaged parts replaced, and coated where suitable |
| Damaged connectors or lifted pads | Loose connections, communication errors | Usually |
| Faulty ICs and processors | Board powers up but will not function correctly | Sometimes – depends on part availability and whether programming is needed |
| Severe fire damage or burnt inner layers | Charred, delaminated or warped board | Rarely – replacement is normally more practical |
What causes a PCB to fail?
- Heat. High panel temperatures and blocked ventilation age components quickly, especially electrolytic capacitors.
- Power surges and supply problems. Voltage spikes, lightning and switching transients after power interruptions can destroy power stages and input circuits.
- Moisture, dust and chemicals. Contamination causes corrosion and leakage between tracks.
- Vibration. Mechanical stress cracks solder joints and connectors over time.
- Age. Components have a finite life. Capacitors dry out, and relays and connectors wear.
- Overloading. Motors or loads drawing more current than a board was designed for will eventually damage it.
We cover these in more detail in 5 Common PCB Failures.
How do you know if a PCB is damaged?
Look out for:
- Bulging, leaking or discoloured capacitors
- Scorch marks, burnt smells or darkened areas on the board
- Cracked components or lifted tracks
- Faults that come and go with temperature or vibration
- Fault codes or alarms on drives, HMIs or controllers that return after a reset
- Equipment that is completely dead even though the supply is present
Visible damage is often only part of the story. A burnt component is frequently the result of a fault elsewhere on the board. That is why proper fault-finding matters. Replacing the obvious burnt part without finding the cause usually means the board fails again.
Repair or replace? How to decide
Repair usually makes sense when:
- A replacement board is expensive or has to be imported.
- Lead times for a new board would leave production down for days or weeks.
- The equipment is obsolete and the manufacturer no longer supplies the board.
- The damage is limited to components, joints or tracks that can be reworked.
Replacement makes more sense when the board is badly fire-damaged, when key programmed parts can’t be sourced, or when the board has failed repeatedly and the equipment is due for an upgrade anyway. For a wider view of this decision, read Repair vs Replace: Making Smarter Industrial Decisions.
How industrial PC board repair works
- Inspection. Visual and microscopic inspection for burnt parts, cracked joints, corrosion and previous repairs.
- Fault-finding. Testing with oscilloscopes, IC testers, function generators and thermal cameras to trace the root cause, not just the symptom.
- Quotation. Once the fault is known, the customer can decide whether repair is worthwhile.
- Component-level repair. Failed parts are desoldered and replaced, including surface-mount (SMD) components, and tracks and joints are reworked.
- Testing. The board is powered up and tested under realistic conditions. Drives and power boards should be tested under load, not just switched on.
Repairing down to the individual part is known as component-level repair. It costs less and fixes the actual cause, instead of swapping whole assemblies.
Can I repair a PC board myself?
Simple faults on low-voltage hobby boards can be repaired at home with a good soldering station and some experience. Industrial boards are a different matter. Drive and power boards store dangerous voltages in their capacitors even after the power is off, use multi-layer boards and fine-pitch SMD parts, and need proper test equipment to confirm the repair. A failed DIY repair can also damage the equipment the board controls.
How to prevent PCB failures
- Keep control panels clean, sealed and properly ventilated.
- Fit surge protection and make sure equipment is correctly earthed.
- Check that panel air-conditioners and fans work, especially in summer.
- Reduce vibration where boards are mounted near machinery.
- Have recurring faults diagnosed properly, instead of resetting and hoping.
Frequently asked questions
Can a burnt PCB be repaired?
Often, yes. If the burning is limited to components and surface tracks, those can be replaced and rebuilt. Boards with deep charring, delamination or burnt inner layers are usually not worth repairing.
Can a cracked PCB be repaired?
Small cracks that break only a few tracks can sometimes be repaired with jumper wires. Large cracks through multi-layer boards are difficult to repair reliably.
Is it cheaper to repair or replace a circuit board?
For industrial boards, repair is usually much cheaper than a new original board, especially for imported or obsolete equipment. The fault-finding step tells you whether that holds for your board.
Do you repair household appliance PCBs?
Motion Tronic’s workshop focuses on industrial electronics, such as drives, servo systems, PLCs, HMIs, power supplies and machine control boards. For fridges, washing machines, gate motors or domestic aircons, a specialist appliance repairer is usually the better option.
Industrial PC board repairs at Motion Tronic
If a failed board is holding up production, our electronics team can help. We carry out industrial PC board repairs to component level, including SMD work, on boards from servo drives, VSDs, PLCs, I/O cards, HMIs and power supplies from most major brands. We carry stock of common components, and repaired boards are tested before they are returned.
Contact Motion Tronic to log a board repair.
Related reading