OFFICE ELECTRONIC EQUIPMENTS
Name of Sector Electronics & Hardware Name of Module Repair and maintenance of Office Electronic Equipments
Minimum Age 18 Years Duration of Course 6 Months
ADU Code ELC702

B.E./ B.Tech. in Electronics / Electronics & Telecommunication/Electronics & Communication with one year experience in the relevant field

(OR)

Diploma in Electronics/ Electronics & Telecommunication / Electronics & Communication from recognized board of technical education with two years experience in the relevant field.

(OR)

NTC/NAC in the relevant trade with three years’ experience respectively in the relevant field



After completion of the module the participant would be able to repair PA System, Photo copying machine & Fax machines, Printer, Scanner and the EPABX system

Objectives :

Testing of electrical parameters, cables and measurements

Select the proper instrument for suitable measurement

Identify and test passive and active electronic components

Practice soldering and de-soldering of various types of electrical and electronic components.

Trouble shoot the faults in the given power supply circuits.

Dismantle, identify and troubleshoot the PA system.

Dismantle, identify and troubleshoot the photo copier faults.

Dismantle, identify and troubleshoot the FAX of the given FAX

Dismantle, identify and troubleshoot the printer faults of the given printers

Dismantle, identify and troubleshoot the scanner faults of the given scanner

Connect various phones to the EPABX system and troubleshoot various simulated faults



Practical Competencies Underpinning Knowledge (Theory)

Basics of electricity and Electrical Cables

  • Practice procedure for electrical and personal safety measures
  • Identify the Live, Neutral and Earth on power Socket
  • Construct a test lamp and use it to mains healthiness
  • Use a Tester to monitor AC power.
  • Measure the voltage between the neutral and ground and rectify earthing
  • Identify and test different ac mains cables
  • Skin the electrical wires /cables
  • Measure the gauge of the wire using SWG
  • Make the mains cable for termination
  • Identify the primary and secondary cells
  • Measure and test the voltages of the given cells/battery using analog and digital Multi-meter
  • Charge and discharge the battery
  • Use a hydro-meter to measure the specific gravity of the secondary battery


Basic terms electric charges, Potential difference, Voltage, Current, and Resistance. Basics of AC & DC. Terms such as positive cycle, negative cycle, Frequency, Time period, RMS, Peak value , peak to peak, instantaneous values, Insulators, conductors and semiconductor. Different type of electrical cables and their specifications.

Multi-meter

  • Cleaning the switch contacts using switch cleaning solution.
  • Testing the fuse.
  • Use the analog and digital Multi-meter to measure the DC voltage by doing measurement at the test points provided.
  • Use the analog and digital Multi-meter to measure AC voltage measurement by doing measurement at the test points provided.
  • Adjust the zero adjustment screw for proper zero setting with the help of a screw driver before using Multi-meter.
  • Replace the battery in the Multi-meter.
  • Replacing the open Fuse with correct rating


Precaution to be taken in handling an analog Multi-meter.

Study of different controls on Multimeter

Principle of operation of Analog Multi-meter.

Precaution to be taken in handling digital Multi-meter

Frequently occurring problems in Analog multimeters and the remedial measures

Precaution to be taken in handling digital Multi-meter,

Familiarization with operation controls of digital Multi-meter

Principle of operation of digital Multi-meter.

Frequently occurring problems in Digital multimeters and the remedial measures

Basic Electronics Components

  • Identify the different types of resistors
  • Measure the resistor values using colour code and verify the reading by measuring in multi-meter
  • Identify the power rating using size
  • Identify different inductors and measure the values using LCR meter
  • Identify the different capacitors and measure capacitance of various capacitors using LCR meter
  • Dismantle and identify the different parts of a relay
  • Identify different types of mains transformers and test them
  • Identify the primary and secondary transformer windings
  • Measure the primary and secondary voltage of different transformers


Resistor-definition, types of resistors, their construction & specific use, color-coding, power rating.

Types of inductors, specifications and applications.

Types of capacitors, specifications and applications

Working principle of a Transformer,

Specifications of a transformer, Step-up, Step down and isolation transformers

Fuse – types, use of fuses and its rating.

Power supply

  • Testing of active components
  • Practice soldering and de-soldering techniques
  • Assemble and test– half wave, full wave & bridge rectifier circuits with and without filter.
  • Identify the different types of fixed positive and negative regulator ICs (78/79 series)
  • Identify the pins
  • Construct a fixed voltage regulator using 78xx/79xx series ICs
  • Construct a variable voltage regulator using LM 723.
  • Observe the output voltage of different IC regulators by varying the input voltage


Basic Electronics active components, testing of components,

Working of half wave, full wave and bridge rectifier circuits.

Voltage Regulator circuit.

Applications of transistor – its uses

MOSFET – precautions when handling.

DIAC, SCR, TRIAC - application

Identify the pin diagram of Voltage regulator ICs

UPS/Inverter

  • Installation of UPS and Inverters
  • Maintenance of batteries
  • Dismantle the UPS and identify the major parts
  • Testing of major components
  • Testing of power modules
  • Charging, discharging and testing of batteries.


Various types of batteries used in UPS and Inverters and their maintenance.

Different types of inverter, UPS, Working principle, specifications, explanation with the help of block diagram.

SMPS

  • Dismantle the given SMPS and find major sections/ ICs components.
  • Measure voltages at vital points
  • Identify various input and output sockets / connectors of the given SMPS.
  • Repairing of SMPS, simulating various faults diagnosing and rectifying it.


Block Diagram of Switch mode power supplies and their working principles

PA system

  • Identify the different devices of PA system
  • Identify the various types of speakers
  • Identify various types of microphones
  • Connect the amplifier with microphone and speakers (Long line connection, line transformers and their connection)
  • Fault finding in pre amplifier sections
  • Fault finding in power amplifier sections
  • Rectification of Humming and whistling problems


Microphones – types, construction, principle of working & characteristics Loud speaker , construction, principle of working, Power Level of loudspeaker, Practical Loudspeakers: Woofer, Tweeter & mid range speakers. Specifications of typical PA (Public Address) System.

various stages of PA System Importance of Impedance matching, types of wires used for connecting mike and speakers. Pre amplifiers, their necessity, wire-less microphones Power amplifiers, components used in power amplifier section and their necessity Multi input amplifiers and their connections.

PHOTO COPIER

  • Operation of a photo copier.
  • Dismantling & Troubleshooting of power supply unit (low & High power)
  • Dismantling and assembling of paper feed mechanism, paper tray, Thermal unit and Toner Unit.
  • Identify the various sensors used in the copier and their fixtures.
  • Dismantling and fitting of drum unit- cleaning of drum unit
  • Fault finding in light unit
  • Identify the faults and repair in the thermal unit.
  • Periodic cleaning and servicing of copier machines
  • Repairing of multipurpose copy printers.


Principle of photo copying Image transfer methods Various types of sensors and their functions. Electrostatic charger and charging of drum assembly. Toner and its properties. Paper trays, Paper feed mechanism and the sensors used for paper movement Effects of light Intensity on charging the drum unit. Principle of Colour Copiers Multipurpose copy printers and heavy duty copiers.

FAX MACHINE

  • Operation of a Fax machine.
  • Telephone line access and phone connection
  • Dismantling & Troubleshooting of power supply unit.
  • Dismantling and assembling of paper feed mechanism, paper tray, Thermal unit and Toner Unit of Fax machine
  • Identify the various sensors used in the Fax machines


Principle of Fax machine. Properties of telephone line, ISDN line Data reception and printing Checksum and its importance Scanning of paper and converting to data. Paper trays, Paper feed mechanism and the sensors used for paper movement

Printer

  • Identification & use of controls/ switches/ sockets of a dot matrix printer
  • Dismantling & Troubleshooting of power supply unit.
  • Identification of internal assembly/ section/parts of DMP
  • Testing of the paper sensor, print head coils, print head needle coil & cleaning of ribbon
  • Identify the faults in DMP & rectify
  • Identification & use of controls/ switches/ sockets of an ink jet printer
  • Interconnect printer to computer & perform printer test & cleaning of an ink cartridge
  • Identification of internal assembly/ section/parts of an ink jet printer
  • Identify the faults of an ink jet printer & rectify
  • Identification & use of controls/ switches/ sockets of an Laser printer
  • Interconnect printer to computer & perform printer test & cleaning of an ink cartridge
  • Identification of internal assembly/ section/parts of Laser printer
  • Identify the faults of an Laser printer & rectify


Printer & its types, principle, parts, working of dot matrix , ink jet & Laser printer, Advantages, disadvantages, cables used to interface the various printers to computer

Scanner

  • Identification & use of controls/ switches/ sockets of scanner
  • Identification of internal assembly of scanner
  • Installation of scanner driver in the computer
  • Interconnect scanner to computer & perform scanner operation and store in the computer
  • Identify the faults in the scanner & rectify


Working principle of scanner, parts. cables used to interface the scanner to computer

EPABX

  • Identification & use of controls on the front panel/Console of EPBAX
  • Identify the terminals of trunk line and extension line and connect the extensions
  • Setting the call transfer, call wait and other facilities available on
  • Dismantle and Identify various sections and the power supply components of the system
  • Simple Programming of EPABX System
  • Make modifications to the existing set up by introducing more connections.


Working principle of Electronic Private Automatic Branch Exchange, applications of EPABX, Block diagram of Electronic Private Automatic Branch Exchange and functions of each block. Methods to connect the trunk line and extension line in a EPABX Call wait, call transfer, conference facility available in a EPABX