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EXERCISE 6 : CONNECTIONS TEST
ACTION
Ensure clip securely on U5.
Go to SETUP and observe settings for Test Type and Mode. Close SETUP.
Press START on the IC Tester.
Observe results and conditions presented around device.
DESCRIPTION
The connections test forms an important part of the IC Tester. Every IC presents different
conditions on its pins. The connections test looks for these conditions to enable the Truth
Table test to be correctly applied. Connections can be related to the logic level seen on the
pins, whether the device has pins shorted to 5V or 0V, Open Circuit or Floating, Linked or
normally driven. The details of how the checks are carried out are included in the
presentation, "ABI Test Methodology", included on the CD.
COMMENT
The connections test on its own may not always highlight the fault but it is an integral part of
the ABI test philosophy, without it you will not be able to effectively diagnose a PCB. With a
truth table test the integrity of the IC is tested, to test it the system needs to obtain the
circuit connections to the IC, these Connections in turn can be used to compare against the
connections of a good IC or against the schematic of the PCB. In some cases the Connections
results are just as important as the Truth Table test as the connections information could
show a problem in the circuit even though the IC test passes the chip you are clipped on.
EXERCISE 7 : VCC DETECTION
ACTION
Press START on the IC Tester and observe indication in Red on Vcc pin (pin 14) and voltage
reading. Press the NO VCC SWITCH and ensure LED lights is on. Observe the V+ indicator on
Pin 14 is now removed and NOV+ indication is now in its place.
Note there are no voltage readings.
