How to check for a short circuit in a PCB circuit board?

August 6 2025

Today, we won't talk about PCB design. Everyone knows that "short circuits" in PCBS are a problem that PCB manufacturers encounter almost every day and are also a rather difficult issue to solve. Whether this problem is improved well or not directly affects the low or high production cost and is also related to the qualified rate of finished products. The first step to improvement is inspection. Here, I will share with you the inspection steps for a short circuit in a PCB circuit board.

1. Manual Soldering Best Practices

For manual soldering operations, developing good habits is essential:
(1).Pre-soldering Inspection
Visually inspect the PCB board before soldering
Use a multimeter to check critical circuits (especially power and ground) for shorts

(2).Post-component Verification
Test power and ground connections with a multimeter after soldering each chip Avoid flicking the soldering iron to prevent solder splashes on chip pins (particularly SMD components) which are difficult to detect

2. PCB Layout Analysis

Open the PCB design file on your computer
Highlight the shorted network to identify:
The closest connection points
Most likely bridging locations
Pay special attention to potential internal IC shorts

3. Circuit Isolation Method

When a short is detected:
Use a sacrificial board for trace cutting (especially effective for single/double-layer boards)
Divide the board into functional blocks
Power each section separately to systematically isolate the problem area

4. Professional Short Circuit Locators

Recommended equipment includes
Singapore PROTEQ CB2000 Short Circuit Tracer
Hong Kong Lingzhi Technology QT50 Short Circuit Detector
UK POLAR ToneOhm950 Multi-layer Board Short Circuit Locator

5. BGA Chip Special Considerations

For BGA chips (where solder joints are hidden under the component and typically on 4+ layer boards):
Implement power segmentation in design using:
Ferrite beads or
0-ohm resistors

This allows easy isolation of individual chips when power-to-ground shorts occur

Note: BGA soldering is particularly challenging - manual soldering often causes adjacent power/ground ball shorts

6. SMD Capacitor Precautions

Exercise extreme caution when soldering small SMD capacitors:
Pay special attention to power filter capacitors (103 or 104 types)
These are numerous and prone to causing power-to-ground shorts
Pre-test all capacitors before soldering as some may be internally shorted