Troubleshooting and Repairing Electronic Circuit
Troubleshooting is the process of isolating and identifying a fault in something so that it can be repaired.
There are lots of variables to consider when troubleshooting a faulty electronic circuit.
In this article we will look at the techniques I have developed to troubleshoot electronic circuits from over 50 years in the electronics industry.
TROUBLESHOOTING TOOLS
- CONTINUITY TESTERS
A continuity tester (found on most multimeters) will allow you to check if there is a break or short in the circuit. Continuity testers apply a voltage across a pair of test probes and measure the current in the circuit. If no current is detected (indicating a short circuit), the continuity tester sounds an audible alarm.
- MULTIMETERS
A multimeter is used to measure voltage, resistance, and current. It’s good to have both a digital multimeter and an analog multimeter on hand, as they each have different applications.
- OSCILLOSCOPES
An oscilloscope is almost indispensable. Oscilloscopes let you to get high resolution look at the electronic signals flowing through your circuit.
- SOLDERING TOOLS
A soldering station or soldering iron is needed to repair solder joints and replace damaged components. A solder sucker or a solder wick can be used to remove the solder joints of faulty components.
- OTHER TOOLS
An X-Acto knife with sharp blades is useful for cutting wires and PCB traces.
To get more ideas on building up your electronics workshop, check out our article on How to Build an Electronics Work Bench.
HOW TO TROUBLESHOOT A CIRCUIT
These are the things I check before diving deep into troubleshooting a circuit:
- Does the PCB or breadboard match the circuit diagram?
- Does the circuit have power?
- Is the circuit getting the correct voltage?
- Is the power supply connected the right way around?
- Are all ICs, transistors, and diodes the correct type?
- Are all resistors and capacitors the correct value?
- Are all polarized components (electrolytic capacitors, diodes, LEDs, etc.) connected the right way around?
- Do all of the solder joints have a good electrical connection?
- Are there any broken traces on the PCB?
Suspect any component that moves or has an interaction with a user. For example, components like potentiometers, switches, and push buttons can become fatigued at the solder joint to the PCB.
Motors have brushes and commutators that wear out.
Look for and test any fuses in the circuit. A fuse may look okay, but you can never be sure until you test it with a continuity tester.
Look for any cut, cracked, or burned PCB traces. Hold the PCB up to strong light to help identify these.
Hobi Elektronika