Sharp 27DV-S100 Service Manual page 67

Hi-Fi audio recording failure.
NO
Are the following signals applied to
the terminals of IC6651?
L-ch
R-ch
Pin (14) Pin (9)
YES
Are 5V and 9V voltages applied at
NO
pins (40) and (58) of IC6651
respectively?
YES
Are there the audio output signals at pins (53) and (57) of IC6651?
YES NO
Are there the serial clock and data
signals at pins (42) and (43) of
IC6651?
YES
Is the voltage at pin (28) of IC6651
at "H" level?
Is the REC AGC ADJ terminal
NO
voltage (1.7V) at pin (37) of IC6651
as specified?
YES
Are there the record FM output
NO
signals from pin (21) to pin (24) of
IC6651 for CH-1, and from pin (21) to
pin (22) of IC6651 for CH-2?
YES
Check the connectors AH and MZ.
FLOW CHART No. 2-16
Check the line between pins (38)/(40) of
IC1301 and pins (14)/(9) of IC6651.
Check the PC5V and PC9V regulator
circuits.
Check the line between pins
NO
(42)/(43) of IC6651 and pins
(18)/(17) of IC2201.
NO Is there the sub-carrier input signal
(3.58MHz, about 900mVp-p) at pin
(45) of IC6651?
NO
Check the line between the emitter of
Q5501 and pin (45) of IC6651.
Replace IC6651.
YES
Is the voltage at pin (29) of IC6651
about 3.7V?
NO
Check the BIAS CTL line.
Is 5V voltage applied at pin (25) of
IC6651?
NO
Check the PC5V line.
Hi-Fi audio playback failure.
Is there the playback envelope output
NO
signal (300mVp-p) at pin (29) of
IC6651?
YES
Replace IC6651.
FLOW CHART No. 2-17
Replace IC6651.
YES
Is there the A-H.SW.P. input signal at
pin (27) of IC6651?
NO
Check the A-H.SW.P. signal line
between pin (27) of IC6651 and pin
(26) of IC2001.