JVC TV-20F242 Service Manual page 40

Noise (it is really back to have
cleaned a head) for a picture
when playback
Whether does
TP4001 FM signal
appear or not?
There is FM signal for
IC4001 88th ,89th
pin?
There is FM signal for
IC4001 28th pin, and
doesn't a noise
appear again?
Video waveform of IC4001
35th pin is 2V, and doesn't
a noise appear again?
Exchange IC701.
No color during self recording
and playback
Whether there is a
video signal for IC4001
35th pin or not?
Whether there is
CHROMA signal for
IC4001 72th pin or not?
Whether there is FM signal
for IC4001 90th pin or not?
Exchange a cylinder unit.
40
NO
YES
NO
YES
NO
YES
NO
YES
NO
YES
NO
YES
NO
YES
Exchange cylinder unit and
CP4001.
Investigate a peripheral
circuit of IC4001.
Investigate a peripheral
circuit of IC4001 46th pin.
Exchange IC4001.
Investigate J4201,J701 and a
video input circuit. (FRONT,
and REAR VIDEO IN)
Investigate IC4001 61st
,62nd pin and X4001.
Investigate CP4001 peripheral
circuit.