NAD C 521BEE, Service Manual

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RF PATTERN TESTING
NAD - C 521BEE PCB TESTING POINTS DIAGRAM
TESTING PROCEDURE
(1) Load the test disc (Sony Test CD YEDS-7) and set the unit into PLAY mode.
(2) Connect the scope to R227 (Pin 15 of U101) and DGND (J144).
Scope setting: Coupling : AC.
Vertical sensitivity : 0.2 V/ div.
Horizontal time base : 0.5 µS/div.
(3) Observe the waveform is 2.0V p-p +/-5% and the eye pattern is at its best shape (see FIG. 1 ).
FIG. 1 (a) FIG. 1 (b) Poor eye pattern
FIG. 1 (C) Good eye pattern
3T 4T 5T — 11T