Sony JMECHA Service Manual ▷ View online
— 33 —
4-2. Tracking Adjustment
1)
Play the tracking alignment tape (XH2-1) (Ref. No. J-5) back.
2)
Adjust TG3 guide until the envelope of entrance side waveform
becomes flat.
becomes flat.
3)
Adjust TG6 guide until the envelope of exit side waveform
becomes flat.
becomes flat.
Note:
Do not touch or adjust TG3 and TG4 guide zenith adjustment screw.
4-3. TG3 Guide Adjustment
1)
Play the tracking alignment tape (XH2-1) (Ref. No. J-5) back.
2)
Run the tape in FWD mode. Confirm that tape runs while
keeping contact with upper flange of TG3. If any clearance is
found between top flange and tape, rotate the adjustment nut
in clockwise direction until tape runs while keeping contact
with upper flange of TG3.
keeping contact with upper flange of TG3. If any clearance is
found between top flange and tape, rotate the adjustment nut
in clockwise direction until tape runs while keeping contact
with upper flange of TG3.
Fig. 4-6
When tape runs while keeping contact with upper flange of
TG3, confirm that the tracking waveform does not change. If
the tracking waveform has poor amplitude at the entrance side
as shown, perform tracking adjustment of entrance side.
TG3, confirm that the tracking waveform does not change. If
the tracking waveform has poor amplitude at the entrance side
as shown, perform tracking adjustment of entrance side.
Fig. 4-7
After entrance side is adjusted, establish the RVS mode. Make
an attempt to rotate the TG3 adjustment nut by 180 degrees in
the counter-clockwise direction in order to confirm that tape
rises upward. Upon confirmation, return the TG3 adjustment
nut to the original position.
an attempt to rotate the TG3 adjustment nut by 180 degrees in
the counter-clockwise direction in order to confirm that tape
rises upward. Upon confirmation, return the TG3 adjustment
nut to the original position.
Fig. 4-8
Fig. 4-4
TG5 guide
TG3 and TG4 guide zenith
adjustment screw.
(Do not touch or rotate.)
adjustment screw.
(Do not touch or rotate.)
TG6 guide
TG4 guide
TG3 guide
TG1 guide
TG2 guide
Fig. 4-5
Normal
Entrance side is
defective
defective
Exit side is defective
Entrance side
Exit side
Adjustment nut (TG3)
TG2 guide
TG1
TG3
TG2
Upper flange
TG1
TG3
TG2
Upper flange
— 34 —
4-4. TG7 Guide Adjustment
1)
Establish the FWD mode. Confirm that tape slack does not
occur in between capstan and TG7 guide. (Specification value:
0.5 mm or less of tape slack) If any tape slack occurs, rotate
the tG7 guide to remove the tape slack.
occur in between capstan and TG7 guide. (Specification value:
0.5 mm or less of tape slack) If any tape slack occurs, rotate
the tG7 guide to remove the tape slack.
2)
Establish the REV mode. Confirm that RF waveform at exit
side is normal. (Refer to Fig. 4-10.)
side is normal. (Refer to Fig. 4-10.)
3)
If the RF waveform at exit side has abnormality, rotate the TG7
nut by 90 degrees in counter-clockwise direction. Then perform
steps 1) and 2) again.
nut by 90 degrees in counter-clockwise direction. Then perform
steps 1) and 2) again.
4-5. Check upon Completion of
Adjustment
1.
Tracking Check
1)
Play the tracking alignment tape (XH2-1) (Ref. No. J-5) back.
2)
Confirm that RF waveform has amplitude of about 0.65A (65%)
in the FWD mode taking the waveform amplitude during CUE/
REV mode as A (= 100%). (Refer to Fig. 4-11.)
in the FWD mode taking the waveform amplitude during CUE/
REV mode as A (= 100%). (Refer to Fig. 4-11.)
Fig. 4-11
3)
Confirm that difference between the minimum amplitude
(E.min) and the maximum amplitude (E.max) of RF waveform
in the FWD mode is 30% or more taking the waveform
amplitude during CUE (or REV) mode as A (= 100%).
(E.min) and the maximum amplitude (E.max) of RF waveform
in the FWD mode is 30% or more taking the waveform
amplitude during CUE (or REV) mode as A (= 100%).
Fig. 4-12
4)
Confirm that the RF waveform does not have excessive
fluctuation.
fluctuation.
Fig. 4-13
Fig. 4-9
TG7 nut
Capstan motor
Tape slack
TG7 guide
TG6 guide
TG5 guide
Pinch roller
Fig. 4-10
0.65A
A: 100%
A
CUE or REV mode
A=100%
FWD mode
E min E max
E.min: Minimum amplitude
E.max: Maximum amplitude
E.max: Maximum amplitude
(E.min – E.min) 30% or (3/10
×
A)
C
C
C
C
A
C 1/8
×
A
— 35 —
2.
CUE/REV Check
1)
Play the tracking alignment tape (XH2-1) (Ref. No. J-5) back
and enter the REV mode. Confirm that pitches between peaks
of RF waveform are equally spaced. (Refer to Fig. 4-14.)
If pitches between peaks of RF waveform are not equal, perform
sections "4-2 Tracking Adjustment" and "4-4. TG7 Guide
Adjustment".
and enter the REV mode. Confirm that pitches between peaks
of RF waveform are equally spaced. (Refer to Fig. 4-14.)
If pitches between peaks of RF waveform are not equal, perform
sections "4-2 Tracking Adjustment" and "4-4. TG7 Guide
Adjustment".
2)
Enter the CUE mode. Confirm that pitches between peaks of
RF waveform are equally spaced. (Refer to Fig. 4-14.) If
pitches between peaks of RF waveform are not equal, perform
sections "4-2 Tracking Adjustment".
RF waveform are equally spaced. (Refer to Fig. 4-14.) If
pitches between peaks of RF waveform are not equal, perform
sections "4-2 Tracking Adjustment".
3.
Rise-up Check
1)
Play the tracking alignment tape (XH2-1) (Ref. No. J-5) back.
2)
Establish the FWD playback mode. Confirm that RF waveform
rises up in two seconds or less. Confirm also at this time that
tape slack does not occur at around pinch roller.
rises up in two seconds or less. Confirm also at this time that
tape slack does not occur at around pinch roller.
3)
Run a tape in CUE/REV mode and FF/REW mode. After that
play the tape back and confirm that RF waveform rises up in
two seconds or less.
play the tape back and confirm that RF waveform rises up in
two seconds or less.
4)
Repeat steps 2) and 3) repeatedly.
Fig. 4-15
4.
Tape Run Check
Run a tape in CUE/REV mode. Confirm to see that major tape curl
does not occur at TG2 lower taper, TG3 upper flange, TG6 upper
flange and TG7 upper flange during CUE/REV mode.
does not occur at TG2 lower taper, TG3 upper flange, TG6 upper
flange and TG7 upper flange during CUE/REV mode.
Fig. 4-16
Fig. 4-14
Capstan motor
Tape slack
TG7 guide
TG6 guide
TG5 guide
Capstan
FWD
TG1
TG3 TG4
TG5 TG6
TG7
TG2
Tape
— 36 —
5-1. Cassette Compartment Block Assy, Drum Assy Block
5. Exploded View
703
704
M901
705
706
701
709
701
708
707
701
702
LS chassis block
assembly
(See page 37)
assembly
(See page 37)
Mechanism chassis block
assembly
(See page 38)
assembly
(See page 38)
(Note)
Note: Type name and part code number of the M901 drum
differ depending on models. Refer to Service Manual
of the respective models.
of the respective models.
Ref. No.
Part No.
Description
Remarks
Ref. No.
Part No.
Description
Remarks
701
3-703-816-14 SCREW (M1.4)
702
X-3950-369-2 CASSETTE COMPARTMENT ASSY
703
3-059-082-01 SPRING, TENSION
704
3-059-208-01 SPRING (CASSETTE COMPARTMENT T)
705
X-3950-370-2 DAMPER ASSY
706
3-059-101-01 RETAINER, LS GUIDE
707
7-624-102-04 STOP RING 1.5, TYPE -E
708
A-7028-133-A MD(J100) SUB ASSY (Y)
709
3-703-816-41 SCREW (M1.4X2.5), SPECIAL HEAD
M901
— Note —
DRUM
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