ISCET Component-Level Troubleshooting 4

Question 1

A technician uses the half-splitting (divide and conquer) method. What is the primary advantage of this technique?

Accepted Answer

It minimizes the number of tests needed to isolate a fault

Answer

It always starts at the power supply

Answer

It eliminates the need for schematics

Answer

It works only on digital circuits

Question 2

Which failure mode of an electrolytic capacitor is indicated by visible bulging or electrolyte leakage?

Accepted Answer

Catastrophic failure due to overvoltage or reversed polarity

Answer

Open circuit failure

Answer

High ESR failure

Answer

Dielectric absorption

Question 3

When checking a transformer for a shorted winding, a technician should measure:

Accepted Answer

Both B and C

Answer

Output AC voltage only

Answer

Primary and secondary DC resistance and compare to specifications

Answer

Insulation resistance between windings with a megohmmeter

Question 4

A PNP transistor has its emitter at +12 V, base at +11.3 V, and collector at +6 V. The transistor is:

Accepted Answer

In the active region

Answer

In cutoff

Answer

In saturation

Answer

Oscillating

Question 5

What does high ESR (Equivalent Series Resistance) in an electrolytic capacitor cause in a switching power supply?

Accepted Answer

Excessive output ripple and overheating of the capacitor

Answer

Increased output voltage

Answer

Reduced switching frequency

Answer

Lower inrush current

Question 6

A technician measures 0 V at the output of a linear voltage regulator IC. The input voltage is correct. What should be checked next?

Accepted Answer

The adjust or enable pin and output capacitor

Answer

The load resistance

Answer

The transformer secondary winding

Answer

The AC line fuse

Question 7

In a digital logic circuit, a gate output is stuck HIGH regardless of input combinations. Which fault is least likely?

Accepted Answer

Open output pin

Answer

Output pin shorted to VCC

Answer

Internal gate failure

Answer

Faulty pull-up resistor holding output high