NAD C660 Service Manual page 28

BETA Measurement circuit
check
After inserting Test Disc (TCD-784),
start playing.
IC108 Pin 86 (RRF):3+/-1.0V?
YES
RRFIN: 2+/0.7V?
(IC108 PIN85)
YES
IC325 Pin 10 (CDR/RWS)="H"?
YES
IC320 Pin 78 (RFBETA):
2+/-1.0V?
YES
K
NO
•Check the connection of IC108 pin 86.
•Check and replace the IC108
(CXA2551R).
•Check the connection of IC109.
NO
•Check and replace the IC109.
•Check the connection of IC320 pin 20.
NO
•Check and replace the IC320 (MICOM).
NO
Is BETA signal nomal?
(IC325 pin 14)
YES
Check the replace the IC325 (BU4052)
-28-
NO
•Check the connection of IC108 pin 82.
•Check and replace the IC108.