NAD C 542 service manual Rf Pattern Testing, C Good eye pattern, b Poor eye pattern

RF PATTERN TESTING

NAD - C 542 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

3T 4T 5T — 11T

FIG. 1 (C) Good eye pattern

- 9 -