Sharp vc-ga56z Service Manual page 46

Video cassette recorder
Table of Contents

Advertisement

FLOW CHART NO.23
No Hi-Fi E-E sound heard.
Is there signal inputted at each
terminal of IC651 as shown in table?
L-ch
R-ch
NO
Front input terminal
pin(15)
pin(10)
NO
Rear input terminal
pin(14)
pin(9)
NO
Tuner audio terminal
pin(48)
YES
Is the voltage 5V applied to pin(40) of IC651,
NO
9V applied to pin(58).
YES
Are serial data and clock signal at pins(43),
NO
(42) of IC651?
YES
NO
Is "L" level applied at pin(36) of IC651?
YES
NO
Is "H" level applied at pin(45) of IC651?
YES
Line output terminal : Is there audio signal outputted at pins(53) and (57) of IC651?
RF output terminal : Is there audio signal outputted at pin(59) of IC651?
YES
Line output terminal : Check line ranging from pins(53) and (57) of IC651 to the audio output
terminal.
RF output terminal : Check line ranging from pin(59) of IC651 to pin(2) of tuner (TU101).
Check the peripheral circuit of front input
terminal.
Check the peripheral circuit of rear input
terminal.
Is there SIF signal from pin(22) of Tuner?
Check the regulator circuit of Hi-Fi 5V
and PC 9V.
Check line between pins(43), (42) of IC651
and pins(17), (18) of IC701.
Check line between pin(36) of IC651 and
pin(21) of IC701.
Is Sub carrier signal (3.58MHz, about 900m
Vp-p) input to pin(45) of IC651?
NO
Check line between emitter of Q501 and
pin(45) of IC651.
NO
Replace IC651.
FLOW CHART NO.24
Hi-Fi sound cannot be recorded (E-E mode is normal).
Is terminal voltage (REC AGC. ADJ.) pin(37) of IC651
normal?
YES
Is record FM signal output to the pins(21) to (24)
(ch-1)/pins(21) and (22) (ch-2) of IC651?
YES
Check the AH-MZ connector.
FLOW CHART NO.25
Hi-Fi sound cannot be played back (E-E mode is normal).
Is playback envelope signal output to the pins(29)
and (30) of IC651? (300 mVp-p)
YES
Replace IC651.
FLOW CHART NO.26
Recording in linear audio is impossible (Hi-Fi E-E mode is normal).
Is audio signal input into the IC201 pin(8)?
YES
Is the pin(99) of IC201 in "L" level?
YES
Does the bias oscillation circuit operate normally?
YES
Is audio signal on which bias signal is superposed
output to the pin(4) of IC201?
YES
Check the AA-MH harness and A/C head.
Replace IC651.
YES
NO
Is the pin(29) of IC651 about 3.7V?
NO
Check Hi-Fi REC CTL line.
NO
Is voltage 5V applied to pin(25) of IC651.
NO
Check line of Hi-Fi 5V.
Replace IC651.
YES
NO
Is A-H.SW.P input into the pin(27) of IC651?
NO
Check the A-H.SW.P. line from the
pin(27) of IC651 to the pin(26) of IC701.
NO
Check the line between the pin(61) of IC651 to
the pin(8) of IC201.
NO
Check the periphery of pin(99) of IC201. (R617)
NO
Check the bias oscillation circuit (T601, Q602, Q603).

Advertisement

Table of Contents
loading

This manual is also suitable for:

Vc-gh96z

Table of Contents