7-
9
Comparison Testing For Digital ICs
1. Set the test signal frequency to 60 Hz.
2. Place a black clip lead from the Tracker 2700's Common terminal to both reference and
suspect IC or boards ground pin.
3. Place the black test lead from the Tracker 2700's B test terminal to the suspect IC's pin. For
this example, start with pin 1 of the suspect IC.
4. Place the red test lead from the Tracker 2700's A test terminal to the reference or known
good IC's pin. For this example, start with pin 1 of the known good IC.
5. Push the Channel A button. Observe the signature. This is the signature of the pin of the
known good component.
6. Push the Select the 10V, 100Ω
ΩΩ
Ω Range.
7. Channel B button. Observe the signature. This is the signature of the pin of the suspect
component.
8. Press the press the Alt button to display the A and B channels on the LCD alternately. If
needed, adjust the Rate to adjust the display speed.
9. Visually compare the reference signature (channel A) with the suspect signature (channel B)
or toggle the Compare Mode on to give PASS/FAIL indication. Make sure to set the compare
tolerance to your desired level. Recommended tolerance is 5.
10. Keep the red probe on pin 1, an input pin. Probe all the other input pins of the suspect
component with the black probe until you have identified all the pins that have signatures that
are the same as pin 1.
11. Move the red probe on pin 2, an output pin. Probe all the other output pins of the suspect
component with the black probe until you have identified all the pins that have signatures that
are the same as pin 2.
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