Read Sharp VC-MH85 (serv.man4) Service Manual online
43
VC-MH705HM/LM
VC-MH815HM/LM,MH85HM
VC-MH715HM,MH835HM
NO
NO
NO
FLOW CHART NO.10 CASSETTE CONTROL TROUBLESHOOTING(2)
A cassette tape is taken in, but ejected at once.
Does the start sensor pulse at pin (87)
of IC701 change from "L" to "H" level
when the cassette tape is loaded?
of IC701 change from "L" to "H" level
when the cassette tape is loaded?
Check line between start sensor and pin
(87) of IC701.
(87) of IC701.
Does the end sensor pulse at pin (86)
of IC701 change from "L" to "H" level
when the cassette tape is loaded?
of IC701 change from "L" to "H" level
when the cassette tape is loaded?
Check line between end sensor and pin
(86) of IC701.
(86) of IC701.
Does the master cam mode shifter
operate normally when the cassette
tape is loaded?
operate normally when the cassette
tape is loaded?
Check line between cam switch and
IC701.
IC701.
Replace IC701.
YES
YES
YES
FLOW CHART NO.11 LOADING MOTOR AND EJECT TROUBLESHOOTING
The cassette tape fails to come out.
Does the capstan motor start when the
EJECT button is pressed?
EJECT button is pressed?
See FLOW CHART NO.12. CAPSTAN
MOTOR TROUBLESHOOTING
MOTOR TROUBLESHOOTING
Does the take-up reel disk turn when the
capstan motor is running?
capstan motor is running?
Check line between take-up reel
sensor and pin(2) of IC701.
sensor and pin(2) of IC701.
Is a "H" level applied at pin(10) of P701
when a reel pulse has been inputted?
when a reel pulse has been inputted?
Check line between pin(92) of IC701
and pin(10) of P701.
and pin(10) of P701.
Is the supply voltage of 12V fed to
pin(8) of P701?
pin(8) of P701?
Is the voltage about 10V sent out from
IC on mechanism?
IC on mechanism?
Check IC on mechanism.
Is the specified voltage applied at the
loading motor terminal?
loading motor terminal?
Check line between IC on mechanism
and loading motor.
and loading motor.
Does the loading motor run?
Replace loading motor.
Replace cassette cam, gear, etc.
YES
YES
YES
Check M 12V lines.
NO
YES
NO
YES
YES
YES
NO
NO
NO
NO
NO
FLOW CHART NO.12 CAPSTAN MOTOR TROUBLESHOOTING
The capstan motor fails to run.
Is the voltage more than about 2.6V
DC given out of pin(29) of IC701?
DC given out of pin(29) of IC701?
Check IC701.
NO
NO
NO
NO
NO
YES
YES
YES
YES
Is the supply voltage of 5V fed to
pin(3) of P701?
pin(3) of P701?
Check PC 5V line.
Is the voltage more than 2.6V DC
sent in pin(9) of P701?
sent in pin(9) of P701?
Check line between pin(9) of P701
and pin(29) of IC701.
and pin(29) of IC701.
Is the voltage of pin(5) of P701 is
1.6~2.7V?
1.6~2.7V?
Check line between the pin(91) of
IC701 and pin(5) of P701.
IC701 and pin(5) of P701.
Is the supply voltage of 12V/20V fed
to pin(2) of P701?
to pin(2) of P701?
YES
Replace capstan motor.
Check MOTOR Vcc line and motor
voltage selector circuit.
voltage selector circuit.
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