JVC TV-20F242 Service Manual page 39

When playback, a screen
doesn't appear
Whether does a screen
of E-E appear or not?
YES
Whether there are PB
Y/C signal for TP4001
or not?
YES
Whether there is FM
signal for IC4001
88th,91st pin or not?
YES
Whether there is a video
signal for IC4001 35th
pin or not?
YES
Investigate Q4007 and the
peripheral circuit.
When playback, a color
doesn't adhere to it
Whether does FM
envelope appear for
TP4001 or not?
YES
Whether does composite
signal appear for IC4001
35th pin or not?
YES
Investigate a television block.
Whether it takes 5V for
NO
IC4001 25, 54, 56,
75, 87th pin or not?
NO
NO
NO
NO
NO
NO
YES
Investigate a power supply
circuit.
Investigate a connection of
IC4001 and cylinder.
Investigate a connection of
IC4001 and cylinder.
Exchange IC4001.
Investigate CP4001 and the
peripheral circuit.
Exchange IC4001.
39