JVC GR-SXM250US, Руководство по обслуживанию

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(No.86721)1-21
3.3 MECHANISM ADJUSTMENT
3.3.1 TAPE TRANSPORT ADJUSTMENT
Mechanism adjustment is needed when DRUM ASSEMBLY or a
part of the tape transport system is replaced. To protect tapes
from damage, first clean the tape transport system, next confirm
that nothing is wrong with the tape transport system by using a
tape that can be disposed of, and then perform adjustment with
alignment tape. Some exterior parts should be removed before
some adjustment procedures, depending on the procedures.
Fig.3-3-1
3.3.2 Back tension
Remove the exterior parts attached to CASSETTE HOUSING
ASSEMBLY so that scales of CASSETTE TORQUE METER can
be read.
• CASE COVER(S),(M) ASSEMBLY
• C. COVER INSIDE
Fig.3-3-2
(1) Set a cassette torque meter onto the deck and measure the
back tension in standard PB mode to confirm that the back
tension is 0.97x10
-3
- 1.71x10
-3
N•m.
(2) If not, replace the tension band.
When the value widely fluctuates in the measurement,
replace the SUPPLY REEL DISK.
(3) With the CASSETTE TORQUE METER, confirm that the
play torque is 1.47x10
-3
- 2.45x10
-3
N•m.
If necessary, replace the center pulley unit.
Fig.3-3-3
3.3.3 Tape pattern
Remove the exterior parts attached to the UPPER CASE
ASSEMBLY so that the guide roller beside the DRUM ASSEMBLY
can be rotated.
• LOWER CASE ASSEMBLY
• TOP OPE UNIT
• CASE COVER(S),(M) ASSEMBLY
• UPPER CASE (S),(M) ASSEMBLY
NOTE:
In performing adjustment, it is recommended that LOWER
CASE ASSEMBLY and TOP OPE UNIT are attached to the
main body for better operation and safety.
Fig.3-3-4
(1) Remove the Cover (JIG) shown on Fig.3-4-1.
(2) Connect the JIG CONNECTOR CABLE to CN25 on the
MAIN BOARD ASSEMBLY as shown on Fig. 3-2-2.
(3) Observe signal at V_TP_FM with external trigger from
V_FF on the JIG CONNECTOR CABLE.
(4) Playback the SP stairstep signal of the alignment tape and
maximize the FM waveform by the tracking button.
(5) Set the tracking control to the center position by simulta-
neously pressing the tracking (-) and (+) buttons and max-
imize the FM waveform by the tracking button.
(6) If the observed FM waveform is not flat, adjust the height of
the SUPPLY of TAKE-UP GUIDE ROLLER with the roller
driver.
POLE BASE (SUP)
(GUIDE ROLLER)
POLE BASE (TU)
(GUIDE ROLLER)
PINCH
ROLLER
TU GUIDE
A/C HEAD
ASSEMBLY
TENSION
POLE
POLE
CASSETTE TORQUE METER
BACK TENSION
0.97x10 -3 - 1.71x10 -3 N
•
m
(10-17gf·cm)
PLAY TORQUE
1.47x10
-3
- 2.45x10
-3
N·m
(15-25gf·cm)
POLE BASE (TU)
(GUIDE ROLLER)
POLE BASE (SUP)
(GUIDE ROLLER)
JIG CONNECTOR CABLE
MAIN CN25 - JIG BOARD
12PIN(V_TP_FM)
13PIN(V_FF)
ALIGNMENT TAPE