TROUBLESHOOTING – TROUBLESHOOTING – THEORY AND PRACTICETHEORY AND PRACTICE

Presented by: Ajay Presented by: Ajay SinghSingh

TROUBLESHOOTINGTROUBLESHOOTING

• Perhaps the most valuable but difficult-to-learn Perhaps the most valuable but difficult-to-learn skill any technical person could have is the skill any technical person could have is the ability to troubleshoot a system.ability to troubleshoot a system.

• Troubleshooting means the act of pinpointing Troubleshooting means the act of pinpointing and correcting problems in any kind of system.and correcting problems in any kind of system.

• Troubleshooters must be able to determine Troubleshooters must be able to determine the cause or causes of a problem simply by the cause or causes of a problem simply by examining its effect.examining its effect.

• Creativity is necessary in examining a problem Creativity is necessary in examining a problem from different perspectives: learning to ask from different perspectives: learning to ask different questions when the “standard” different questions when the “standard” questions don’t lead to fruitful answers.questions don’t lead to fruitful answers.

BASIC QUESTIONS TO ASK BEFORE BASIC QUESTIONS TO ASK BEFORE PROCEEDINGPROCEEDING

• Has the system ever worked before? If Has the system ever worked before? If yes, has anything happened to it since yes, has anything happened to it since then that could cause the problem?then that could cause the problem?

• Has this system proven itself to be prone Has this system proven itself to be prone to certain types of failure?to certain types of failure?

• How urgent is the need for repair?How urgent is the need for repair?• What are the What are the safety concernssafety concerns, before I , before I

start troubleshooting?start troubleshooting?• What are the process quality concerns, What are the process quality concerns,

before I start troubleshooting (what can I before I start troubleshooting (what can I do without causing interruptions in do without causing interruptions in production)production)

GENERAL TROUBLESHOOTING TIPSGENERAL TROUBLESHOOTING TIPS

• Prior occurrencePrior occurrence

• Recent alterationsRecent alterations

• Function vs. non-functionFunction vs. non-function

• HypothesizeHypothesize

SPECIFIC TROUBLESHOOTING TECHNIQUESSPECIFIC TROUBLESHOOTING TECHNIQUES

• Swap identical componentsSwap identical components

• Remove parallel componentsRemove parallel components

• Divide system into sections and test those Divide system into sections and test those sectionssections

• Simplify and rebuildSimplify and rebuild

LIKELY FAILURES IN PROVEN SYSTEMSLIKELY FAILURES IN PROVEN SYSTEMS

• Operator error- Operator error- A frequent cause of system failure is error A frequent cause of system failure is error on the part of those human beings operating a system.on the part of those human beings operating a system.

• Bad wire connections- Bad wire connections- i.e. open or shortedi.e. open or shorted • Power supply problems- Power supply problems- these generally consists of these generally consists of

tripped over current protection device or damage due to over tripped over current protection device or damage due to over heating.heating.

• Active components- Active components- such as amplification devices tend such as amplification devices tend to fail with greater regularity than passive device.to fail with greater regularity than passive device.

• Passive components- Passive components- Passive components are the Passive components are the most rugged of all, even though the followings components have most rugged of all, even though the followings components have to be failure possibilities in a order most likely to least likelyto be failure possibilities in a order most likely to least likely

• Capacitors – shortedCapacitors – shorted• Diodes – open (rectifying diodes) , or shorted (Zener diodes)Diodes – open (rectifying diodes) , or shorted (Zener diodes)• Inductor or transformer windings open or shorted to conductive coreInductor or transformer windings open or shorted to conductive core• Resistor open.Resistor open.

LIKELY FAILURES IN UNPORVEN LIKELY FAILURES IN UNPORVEN SYSTEMSYSTEM• Wiring problems- Wiring problems- bad connections are usually bad connections are usually

assembly error, such as connection to the wrong point or assembly error, such as connection to the wrong point or poor connector fabricationpoor connector fabrication

• Power supply problems- Power supply problems- Blown fuses and Blown fuses and tripped circuit breakers are likely sources of troubletripped circuit breakers are likely sources of trouble

• Defective components- Defective components- any type of any type of component-active or passive-may be found defective or of component-active or passive-may be found defective or of imprecise valueimprecise value

• Improper system configuration- Improper system configuration- such such as programming error, incorrect time delay relay as programming error, incorrect time delay relay settings, limit switch calibrations etc.settings, limit switch calibrations etc.

• Design error –Design error –perhaps the most difficult to perhaps the most difficult to pinpoint and the slowest to be recognized is the pinpoint and the slowest to be recognized is the problem of design errorproblem of design error

Thank you very much.Thank you very much.

This presentation was not to teach a This presentation was not to teach a lesson to somebody rather to share lesson to somebody rather to share our knowledge among us for a our knowledge among us for a common goal of being a proficient common goal of being a proficient professional engineer in NEPAL.professional engineer in NEPAL.