3D Wheel Alignment Camera Board Short-Circuit Repair

Fault Description

”My SM-V2 3D wheel aligner (with 5MP cameras) had a short circuit, and it blew out one of the camera boards.“

Diagnosis & Repair Process

The customer reported a short-circuit failure affecting one 5MP camera channel in an SM-V2 3D wheel-alignment machine.

This type of module may combine an illumination board, camera-control board, image-sensor board, heat sink, standoffs, and ribbon interconnects. Each layer must be documented before disassembly so orientation and spacing can be restored correctly.

1. Inspection and Diagnostics

Step 1: Disassembly and Visual Inspection

• Disassembled the multi-layer stack structure to inspect the LED illumination board and camera control board separately.

• Removed the boards from the aluminum heat sink and placed them on an anti-static mat for visual inspection.

• Inspection Image (Figure 1): Displays the fully disassembled assembly, including the main LED PCB, small camera sensor board, aluminum heat sink, brass standoffs, and ribbon cable.

Step 2: Short Circuit Localization

• Focused troubleshooting on the small camera control board since it manages USB power input and onboard power distribution.

• Applied controlled power injection using a benchtop power supply (0V–30V / 0A–5A), injecting 1V into the main 5V power rail while monitoring current draw.

• Scanned the board using a high-resolution thermal imaging camera.

Inspection Image (Figure 2): Shows a close-up of the camera PCB with a thermal overlay revealing a distinct hotspot. A 0805 SMD capacitor (10μF) glows bright orange, confirming heavy heat generation from a direct short. Surrounding components remained cool (blue/green). Multimeter testing confirmed near 0 Ω resistance across the capacitor.

2. Repair Measures

Inspection Image (Figure 3): High-magnification microscope view showing the repair operation. Removed the shorted 0805 capacitor and found that the copper trace beneath it had overheated and lifted.

Trace Reconstruction: Manually reconstructed the lifted trace using fine gold wire and a micro-soldering tip to restore circuit continuity.

Component Replacement: Placed a new 10μF 0805 capacitor across the clean pad and the end of the reconstructed trace for final soldering.

3. Test Records

A current-limited low-voltage injection test may be used on the isolated rail after its normal voltage and polarity are confirmed. Thermal imaging, freeze spray, or voltage-drop probing can then help narrow the heat-producing branch.

Static Resistance Measurement: Resistance between the 5V power rail and ground returned to a normal range (several kilohms) instead of 0 Ω.

Power-On Monitoring: Gradually increased supply voltage to 5V. Current draw stabilized within normal operating limits (≈ 350 mA).

4. Final Results

Reassembled the repaired circuit board back into its multi-layer stack structure.

• Final Result Image (Figure 4): Shows the fully reassembled unit operating under test:

  • LED Illumination Test: All 64 LEDs in the 8×8 IR array illuminated correctly.

  • Camera Functionality Test: The laptop screen displays a clear live image feed captured by the 5MP camera sensor, confirming complete functional restoration.