Eldig develops test programs for its own equipment (AFT, Vision, etc.) and for automatic programmable equipment.


An electronic, electrical or electromechanical device consists of one or more electronic boards, electrical circuitry, mechanical, electromechanical and pneumatic parts; consequently, the testing of electronic equipment consists of a series of tests, first on the individual parts and then on the end set.
The first test carried out on the electronic boards must check the absence of short circuits, the integrity of the assembled components, their presence and correct arrangement on the plate, the operation of each individual component.
Typically, an automatic and programmable device that uses the in-circuit testing technique is used to carry out the first electronic test.

Eldig develops testing programs for its own equipment (AFT, Vision, etc.) and carries out tests on automatic programmable equipment. In any case, the device provided for each board to test includes:

  • Design, construction and execution of a fixture with a possible bed of nails, activated manually or pneumatically, and specific hardware
  • Testing programme carried out with the language of the specific test device
  • Complete documentation
  • Development of logical patterns

The sequence of the standard electronic tests on in-circuit ATE is as follows:
Parametric electronic tests.
The parametric test implies the use of a bed of nails (fixture) that connects all the resources of the test machine to the board to be tested. The implemented tests are subdivided into:
Unpowered tests, separated in turn into:

  • Preliminary electronic tests, to determine:
    • Channel contacting test, to check the accuracy of the interconnections between the board being tested and the instrumentation
    • Short tests, to check that there are no residues from welding or of other types
  • Analog tests, to test the following components:
    • Resistances, of which the accuracy of the impedance value is tested
    • Condensers, of which the capacitive value is measured
    • Inductance, for which the effective value is measured
    • Diodes, of which the correct layout and the voltage drop are tested
    • Transistors, of which the layout and parameters associated to it are tested
    • Zener, like for the diodes, plus the zener voltage value
    • Mosfet, with the conduction/interdiction and various other tests

Powered electronic tests, with tests applied only if the previous tests were successful, separated into:

  • Analog Functional Tests:
    • Linear and Switching voltage regulators
    • Operational and Comparators
    • Oscillators
  • Digital Tests:
    • All the logical circuits, on which input stimulations are carried out and the outputs are monitored.

The sequence of the standard electronic tests on functional testing equipment is as follows:

  • Preparation for any manual calibrations (trimmer, switch, etc.)
  • Power supply activation, with a functional check of the voltages generated on the board
  • Test preparation commands
  • Sequence of tests that stimulate all the parts of the circuit, with output control
  • Forced interruption of the test in case of inadequate response of the board being tested
  • Final diagnostics saved
  • Test result Pass/Fail

Furthermore, Eldig produces equipment for the following electronic testing devices:

It is part of the latest automatic electronic testing equipment:

  • In-circuit/functional system with direct hybrid Analog/Digital channels
  • Programmable digital channel 0->5V/+12V->-12V
  • Possibility of Open-Fix test on integrated circuits-connectors
  • High voltage functional tests via HV module
  • External instrumentation management via IEEE448
  • Data archiving in ASCI-EXCEL format
  • WINDOWS NT 4.0/XP operating system
  • Test list

Included in the sector of multipurpose electronic testing equipment with a high level of diffusion and consisting of:

  • In-circuit/functional system with multiplexed hybrid Analog/Digital channels
  • Digital channel programmable between +12v and -12v
  • Logical tests on integrated circuits
  • Functional tests with external instrumentation management
  • OS2 operating system

Included in the sector of low to medium cost electronic testing devices with the following characteristics:

  • In-circuit/functional system with multiplexed hybrid Analog/Digital channels
  • Digital channel programmable between +12v and -12v
  • Logical tests on integrated circuits
  • Functional tests with external instrumentation management
  • Functional tests with serial commands from P.C.
  • External instrumentation management with serial protocol
  • WIN98 operating system with final test programme in Visual C

For the devices with the Tecnost brand, Eldig testing also provides technical assistance. 



Before speaking about the test, it is worth giving an informal definition of fault:

“fault means any event that makes a system behave in way that is different from its original one."

In this context, the word test means a procedure to search, identify and locate faults.


Before starting the test of the individual components it is worth carrying out some fundamental checks in order to the avoid false diagnoses for the tests that will be conducted subsequently.

The preliminary tests are:


The Analog In-Circuit tests check the quality of the analog components contacted, allowing the identification of the abnormal individual components.

The Analog In-Circuit Tests include the:

The guarding in turn may be:

Test methodologies of analog components

The components typically used in the analog board are:

The following pages show the checks advised for the components listed above.

Note: The tests apply in the condition of isolated component.