Phase Of Control Head (X Value); Remarks; Cleaning; Applying Oil And Grease - JVC GR-FXM270A Service Manual

2.4.4 Phase of control head (X value)

1. Connect the jig connector cable to CN25 on the MAIN
board.
2. Playback the SP stairstep signal of the alignment tape
and observe signal at V.TP FM with external trigger from
V.FF on the jig connector cable.
3. Operate the tracking button in the center and manual
tracking mode by pressing the tracking (+) and (–) but-
tons and confirm that the FM output level is maximum
at the center position as shown in Fig. 2-4-8.
4. If necessary, slightly loosen the setscrews D and E and
insert the Tweezers into the notch and guide hole to
move the A/C head fully in the direction of the capstan
to the extent.
5. Gradually move the A/C head toward the drum to find
the position where the FM output level maximum for the
first time (a' – b' in Fig. 2-4-8).
6. Fine adjust the phase of the A/C head and tighten the
screws D and E at the point a.
A/C head
Screw D
Fig. 2-4-7 Phase of control head
a
Adjusting
point
FM output
Direction of capstan
A/C head phase
Fig. 2-4-8 Phase adjustment point of control head
2-9
Insert the
Tweezers
Screw E
b
Max
Zero
Direction of drum
2.5

REMARKS

2.5.1 Cleaning

1. For cleaning of the upper drum (particularly video heads),
use fine-woven cotton cloth or Kimwipe with alcohol
soaks through. Do not move the cloth but turn the upper
drum counterclockwise.
Note: Make sure not to move the cloth in the vertical
direction to the video head, since it may cause
damage of the video heads.
2. For cleaning of parts of the tape transport system except
the upper drum, use fine-woven cotton cloth or cotton
swab soaked alcohol.
3. After cleaning, confirm that the cleaned parts are com-
pletely dry before loading the deck with cassette tape.

2.5.2 Applying oil and grease

1. Periodical oiling and greasing are not required but should
be done to new parts when replacing. If oil and grease
on the other parts of the other party are old and dirty,
wipe them clean and apply new oil or grease.
2. For parts and points to apply oil and grease, refer to the
exploded view of the mechanism assembly (M3).
Table 1-5-1 specifies oil and grease to be used.
3. When oiling, clean the objective parts with alcohol first
and apply one or two drop(s) of oil. Too much oiling
causes rotary parts to slip because of oil leakage.
Classification Name
Grease KYODO-SH-P
Oil YTU94027
Table 2-5-1 Specific oil and grease to be used

2.5.3 Checkup

After replacement of the supply reel disk and tension band,
make sure to inspect back tension according to the adjust-
ment procedure of MECHANISM ADJUSTMENT section.
Symbol in drawing
AA
BB