The US Navy Electronics 6-Step Troubleshooting Method

The U.S. Navy's Six-Step Troubleshooting Method for electronics systems. This systematic approach is used to efficiently identify and resolve faults in electronic equipment. The six steps are:

1. Symptom Recognition – Identify that a malfunction exists through user reports, system indicators, or performance issues.

2. Symptom Elaboration – Gather more detailed information about the problem. Ask questions like: When did it start? Under what conditions? Is it intermittent or constant?

3. Listing Probable Faulty Functions – Determine which functions or subsystems could be responsible for the observed symptoms.

4. Localizing the Faulty Function – Narrow down the faulty function to a specific section or module of the equipment.

5. Localizing the Trouble to a Defective Component – Within the faulty section, isolate the exact component (e.g., resistor, capacitor, IC) causing the issue.

6. Failure Analysis – Once the component is replaced or repaired, analyze why it failed to prevent recurrence and improve system reliability.

Example:

Let’s say you’re working on a shipboard radar system that has stopped displaying target data on the screen.

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⚙️ Scenario: Radar Display Not Showing Targets

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1. Symptom Recognition

The radar operator reports that no targets are appearing on the radar display. You confirm that the screen is on but shows no contacts.

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2. Symptom Elaboration

You ask additional questions and check other indicators:

• The screen is working (not blank).

• The radar sweep line is visible.

• No alarm tones are sounding.

• The problem started after a heavy rainstorm.

• Power supplies show normal voltages.

This helps you rule out certain problems like a total power loss.

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3. Listing Probable Faulty Functions

You brainstorm which parts of the system could cause this issue:

• The transmitter isn’t sending pulses.

• The antenna isn’t rotating or scanning.

• The receiver isn’t picking up echoes.

• The signal processor isn't converting data correctly.

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4. Localizing the Faulty Function

You systematically test these possibilities:

• You check the antenna — it’s rotating fine.

• You measure RF output — the transmitter is not emitting.

• BINGO — the issue is probably in the transmitter section.

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5. Localizing the Trouble to a Defective Component

Within the transmitter, you check:

• Fuses and power inputs — all good.

• The modulator circuit — appears unresponsive.

• You narrow it down to a faulty pulse-forming network (PFN) that isn’t triggering the transmitter tube.

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6. Failure Analysis

After replacing the PFN, the transmitter works and radar contacts return to the screen. Upon inspection, the PFN had water intrusion, likely due to a weather seal failure during the rainstorm.

Conclusion: You document the failure and recommend improved sealing and regular inspection of weather seals in the maintenance schedule.