Category:Common Issues

Troubleshooting Basics.

Introduction:

This article is a starting point that can and should be expanded an elaborated on. Please be aware there might be omissions or oversights, and not all instructions may apply to your specifis issue or device. Before all, apply a generous amount of judgement.

Troubleshooting Basics - Steps.

Try the easiest thing first.

Don't trust the other guy (who worked on it before you).

90% of problems are human error or oversight.


 * Based on AvE troubleshooting 101 video, credit:

Formalized extended troubleshooting procedures:

These are some “best practices” that have proven themselves in many real world situations. The first steps are analytical and preventative actions that can (should...) always be taken, regardless of what the issue on hand is.

Document the case as presented by the client. Research the failure and repair history of the equipement. Analyze and document the current state of functionality as positives or negatives.

Now you have a dossier for the equipment that you can refer to for your technical analysis.

In order to troubleshoot safely:

Set up an environment that prevents error, overload or further damage.

Other examples:

Disconnect the equipment from the mains power.

Place the equipment on an anti-static work area.

Disconnect any batteries.

Remove any storage.

All in order to minimize the risk of cumulative and/or collateral damage. Once the equipment is well documented and secured, you can proceed to technical analysis of the issues.

Technical analysis:

Start with a complete visual inspection. There may not be a singular fault: some defects are compound, involve multiple components, be on both sides of a board etc. A guide to visual inspection of electronic componenents: 

Document your findings. A simple sketch/diagram of where the visually-damaged components are is enough, and is useful further on in the process and to communicate with the client.

If visible defects are found, verify individual components and adjacent/connected components with electronic measurements to determine which ones are faulty and to what extent. A component may look bad, but be working fine, e.g. a connector that is slightly bent but is not otherwise compromised. If no visible defects are found, proceed to doing measurements on the electronics.

Electronic measurements:

Continuity test:

The most straightforward, easiest and most widely used measurement is the continuity test, which determines if a signal or current can travel freely between components. Failing continuity indicates if a component, connector or trace is broken. A continuity test can be done with something as simple as a battery and an LED (with the appropriate resistor)

Current flow test:

Testing current flow requires testing equipment that can measure voltage, amperage, and/or resistance. In order to succesfully test current flow you need to have a basic understanding of electrical components such as resistors, diodes, capacitors, transistors etc., and some idea of what is supposed to happen with the current inside the equipment. An original schematic is very useful for this, but wihout a schemtic it is still possible to infer various functionalities based on the design of the device. Refer to electronic measurements guides, your test equipment documentation, and available schemtics for operational details. If original and/or matching documentation and/or schematics are not available, it is possible to us “nearest neighbor” documentation, however be aware there are often significant differences between iterations of equipment.

Once a fault has been located, verified and isolated, the next step is the actual repair, which of course is a procedure i itself.