Sherwood RX-772 Service Manual page 14

Symptom
AMP Sound Dead.
1. "LEFT" Channel dead.
2. "RIGHT" Channel dead.
Digi-Link Failure.
Remote Controller Failure.
FM Failure.
AM Failure.
Stereo Effect Failure.
Stereo does not light up.
Tuner Sound Dead.
1. "L / R" Channel dead.
2. "LEFT" Channel dead.
3. "RIGHT" Channel dead.
Cause and Remedy
A) Signal Mute TR's inferior.
B) Connector disconnection & disjunction.
Change or close insertion of the connector.
C) Speaker wire's disjunction.
Close insertion of the speaker wire.
D) Signal switching IC check.
1. I.C voltage check ( +12 )V, ( -12 )V
2. Switching I.C control data, clk check.
3. Switching I.C signal IN/OUT check.
A) Digi-link line disconnection check.
Digi-Link IN/OUT circuit check.
B) Micom Interface Port Check.
1. ¥ ì -COM I.C B+(5 )V check.
2 . Digi-link data I/O data check.
A) Battery check.
B) RMC I.C & Resonator inferior.
1. ¥ ì -COM I.C B+( 5 )V check.
2. REMOCON data check.
A) FM MUTE adjustment inferior.
B) PLL Line check.
1. PLL control data check. (Data/CE/Clock)
C) TUNER B+ voltage inferior.
D) ¥ ì -COM I.C & Resonator inferior.
1. ¥ ì -COM I.C B+( 5 )V check.
A) AM V.T voltage inferior.
B) PLL Line check.
1. PLL control data check (Data/CE/Clock)
C) TUNER B+ voltage inferior.
D) ¥ ì -COM I.C & Resonator inferior.
1. ¥ ì -COM I.C B+( 5 )V check.
A) FM TUNED Inferior.
B) ¥ ì -COM I.C & Resonator inferior.
1. ¥ ì -COM IC B+( 5 )V check
C) STEREO adjustment inferior.
D) FM MUTE adjustment inferior.
E) ¥ ì -COM I.C & Resonator inferior.
1. ¥ ì -COM IC B+( 5 )V check
A) MUTE TR inferior.
B) Connector's disconnection or disjunction.
Change or Close insertion of the connector.
Ref No.
Q 352( L, R), Q318(L, R)
CP101, CN102
I.C No. ( 101 )
I.C Pin No. ( 28, 1 )
I.C Pin No. ( 15, 14 )
R ( 262, 242 ), D ( 201 )
I.C NO. (201 ) / I.C Pin No. ( 38 )
I.C Pin No. ( 15, 16 )
I.C NO. (201 ) / I.C Pin No. ( 62)
IC201 Pin No. (26, 23, 25)
R205
I.C No. ( 201 )
I.C Pin No. ( 15, 16 )
IC201 Pin No. (26, 23, 25)
R205
I.C No. ( 201 )
I.C Pin No. ( 15, 16 )
R278, IC201 Pin No(34)
I.C No. ( 201 )
I.C Pin No. ( 15,16 )
R280, IC201 Pin No(35)
I.C201 PIN No.(27)
I.C No. ( 201 )
I.C Pin No. ( 15,16 )
Q204