Troubleshooting - Sharp vc-ga56z Service Manual

MECHANISM TROUBLESHOOTING
1. FF/REW FAILURE (NO TAPE WINDING)
Press FF key.
NO
Is master cam at Does loading
FF position ? motor operate?
YES
YES
Modes changing
smoothly through
cam switch ?
YES
Loading motor
control system
in trouble.
Does capstan
NO Are Vco 23V and
motor turn in FF (or
Vcc 5V applied ?
REW) direction ?
YES YES
Replace the
capstan motor.
Are idler wheel
NO
Replace the idler
ass'y and reel disk
ass'y.
in mesh ?
YES
Is the pulse
NO Replace the reel
outputted from reel
sensor.
sensor ?
YES
The cassette tape
is presumably
damaged.
NO NO
Is voltage applied Voltage supply
to loading motor ? system in trouble.
YES
Loading motor is
NO
damaged. Replace
it.
Mode sensor
system in trouble
or master cam
malpositioned.
NO Voltage supply
system in trouble.
2. REC/PLAY FAILURE (MODE RELEASE)
NO
Is the master cam Does loading
at PB position ? motor operate ?
YES
YES
Modes changing
smoothly through
cam switch ?
YES
Loading motor
control system
in trouble.
NO Are Vco 23V and
Does capstan
Vcc 5V applied ?
motor turn ?
YES YES
Replace the
capstan motor.
Are idler wheel
NO
Replace the idler
ass'y and reel disk
ass'y.
in mesh ?
YES
Is the pulse
NO Replace the reel
outputted from reel
sensor.
sensor ?
YES
Check main PWB.
NO NO
Is voltage applied Voltage supply
to loading motor ? system in trouble.
YES
Loading motor is
damaged. Replace
it.
NO Voltage supply
system in trouble.