Sharp 13VT-L200 Service Manual page 48

A
Only PB mode inoperetive.
Check X7701, C7705 and
C7706.
Check the capstan FG
signal line between AM
connector and IC7701.
Does PB CTL signal
YES
appear at pin (97) of
IC7701?
NO
Does CTL amplifier circuit
of IC7701 (pins (92) to
(97)) operate normally? NO
(Does the noise appear at
pin (97) when touch
R7774 by hand?)
YES
Is the FFC AA-MH NO
Replace the FFC AA-MH.
normal?
YES
NO
Does the A/C head
Replace A/C head.
operate normally?
YES
Adjust the height of the
A/C head.
CAPSTAN SERVO TROUBLESHOOTING
Capstan servo does not function.
Are REC and /or PB
mode inoperative?
Is there 16MHz oscillation
NO
at pins (38) and (39) of
IC7701.
NO
Does there appear the
capstan FG signal at pin
(85) of IC7701?
Is there capstan control
signal at pin (77) of
IC7701?
Is there the capstan
control voltage applied to
pin (4) of AC connector?
Replace IC7701.
YES
Is pin (75) of IC7701
normal?
Check " A "
Check " B "
Replace the capstan
motor.
Only REC mode inoperetive.
YES
YES
YES
NO
Replace IC7701.
YES
NO
NO
Replace IC7701.
YES
In case of NO GOOD
FLOW CHART NO.1-11
B
Does there appear the V-
NO
sync. at pin (84) at
IC7701?
YES
Is there REC CTL signal
YES
output at pins (92), (91) of
IC7701?
NO
Check the composite
sync. signal at pin (14) of
IC2201, Q2201 and
Q2202, up to pin (84) of
IC7701.