Read Sharp 37VT-26H Service Manual online
37VT-26H(GY)
52
NO
YES
FLOWCHARTNO. 1-6
CAPSTAN MOTOR TROUBLESHOOTING
The capstan motor fails to run.
FLOWCHART NO. 1-7
TAKE-UP REEL PULSE GENERATOR TROUBLESHOOTING
No reel sensor pulse appears.
Is 5V at pin (8) of connector AC ?
Check the STAND-BY 5V line.
NO
Is 8V, 12V or 23V at pin (5) of
connector AC ?
Check 8V, 12V and/or 23V lines.
NO
Check between the connector AC and
pin (76) of IC2001, and between the
connector AC and pin (73) of IC2001.
YES
NO
YES
Check pin (74) of IC2001.
Is the voltage more than about 2.6V
given to pin (4) of connector AC ?
YES
Check/replace the capstan motor.
YES
Is the voltage at pin (3) of connector
AC 1.6~2.7V ?
Insert the cassette, and
put the unit in FF or REW
mode.
NO
Are there the take
up/supply reel pulses at
the collectors of
D7702/D7703 ?
Check between D7702
and pin (80) of IC2001,
between D7703 and pin
(79) of IC2001.
Check/Replace the take
up/supply reel sensors
D7702/D7703.
4.2V
0
4.4V
0
D-PG
D-FG
about
4.6V
FLOWCHART NO. 1-8
HEAD SWITCHING PULSE TROUBLESHOOTING
No head switching pulse.
NO
YES
YES
YES
Is the drum motor
rotating ?
Are the drum PG and
drum FG signal inputted
to pins (90) and (89) of
IC2001, respectively ?
NO
Are there the drum PG
and drum FG signals at
pins (3) and (5) of
connector AD ?
Check pin (18) of IC2001
and signal line of head
switching pulse.
NO
See FLOW CHART NO.
1-9.
Check PG/FG signal lines
all the way up to pins (90)
and (89) of IC2001.
Check the harness
AD-ME and the drum
motor unit.
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