Sharp VC-MH705HM/LM Service Manual page 29

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FLOW CHART NO.21 Hi-Fi SOUND MODE TROUBLESHOOTING(1)
<For Hi-Fi mode>
Is there audio signal inputted at each input
terminal as shown in table?
Tuner input terminal. IC2501 IC2501
pin(16) pin(15)
Decoder signal input
IC651 IC651
terminal.
pin(14) pin(9)
Is there audio signal outputted at pin (57)
of IC651?
YES
Is there audio signal outputted at pins (5),
(53) of IC651?
YES
No Hi-Fi E-E sound heard
Check line ranging from pins (31),(30) of
IC1701 (NICAM/GR), to the each input
terminal of IC2501.
Check line ranging from pins (39),(40) of
NO
IC2501 (decoder circuit) or audio input
terminal to the each input
terminal of IC651.
NO
Check PC 5V and Hi-Fi 9V lines.
NO
Is the supply voltage of PC 5V fed to pins(24),
(40) and 9V fed to pin (58) of IC651?
YES
Are there the serial data and clock at pins
NO
(42) and (43) of IC651?
NO
Check line between pins (42),(43) of IC651
and pins (21),(27) of IC701?
Check line between pins (57)and (53) of
IC651.
Digitized in Heiloo the Netherlands
<For normal mode>
Is there audio signal inputted at each input
terminal of IC201 as shown in table?
NO
U/V tuner audio input terminal. pin(9)
NO
Aux input terminal pin(8)
YES
Is there audio signal outputted at pins (11),
NO
of IC201?
YES
Is there audio signal outputted at pin (62)
NO
of IC651?
YES
Line output terminal : Is there audio signal outputted at pins (59) and (53) of IC651?
RF output terminal : Is there audio signal outputted at pin(59) of IC651?
YES
Line output terminal
Check line ranging from pins (59) and (53) of IC651 to pins (2) and (1) of IC2501.
RF output terminal
Check line ranging from pin (59) of IC651 to the audio input terminal of tuner TU101.
Check line ranging from A-out pin (21),of
TU101.
Check line ranging from pin (61) of IC651.
Replace IC201.
YES
Is there "L" level at pin(99) of IC201?.
NO
Check line between pin (36) of IC651 and
pin(81) of IC701.
Check line between pin (11) of IC201 and
pin (62) of IC651
NO
YES
Is there "L" level at pin(8) of IC651?.
NO
Check line between pin (8) of IC651 and
pin (21) of IC701
Replace IC651.
Not for sale!
6/17/2019