JVC TV-20F242 Service Manual page 43

A audio can't record it
A bias level with L4003
is OK (approximately
40Vp-p)
YES
Whether there is an
audio signal for
IC4001 80th pin or
not?
YES
Whether there is an
audio signal for IC4001
97th pin or not?
YES
Whether there is a
signal for IC4001
98th pin or not?
YES
Whether there is a
signal for IC4001
106t
h pin or not?
YES
Investigate a lead line and
connector of A/C head.
NO
NO
NO
NO
NO
Investigate Q4005 and
Q4006 peripheral circuit.
Investigate IC5501 and the
peripheral circuit.
Investigate IC4001 and the
peripheral circuit.
Investigate IC4001 and the
peripheral circuit.
Exchange IC4001.
43