JVC GR-SXM277UA Service Manual page 37

4.3.5 Phase of control head (X value)
Note:
Remove the exterior parts attached to the UPPER CASE
ASSEMBLY so that the screws around the A/C HEAD
ASSEMBLY can be tighten or loosen.
(1) Connect the JIG CONNECTOR CABLE to CN25 on the
MAIN BOARD ASSEMBLY.
(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 (-) buttons
and confirm that the FM output level is maximum at
the center position as shown in Fig. 4-3-10.
(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. 4-3-10).
(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.4-3-9
A
ADJUSTING
POINT
FM OUTPUT
DIRECTION OF CAPSTAN
A/C HEAD PHASE
Fig.4-3-10
INSERT THE
TWEEZERS
SCREW E
B
MAX
ZERO
DIRECTION OF DRUM
4.4 ELECTRICAL ADJUSTMENT
Electrical adjustment is performed by using a personal computer
and software for SERVICE SUPPORT SYSTEM. Read RE-
ADME.TXT file to use the software properly.
As for the connection of cables, see "4.2 JIG CONNECTOR
CABLE CONNECTION".
4.4.1 B/W VF ASSEMBLY (E. VF) ADJUSTMENT
Referring to "SEC. 3 DISASSEMBLY" and connect the E. VF
WIRE to CN12 of the MAIN BOARD ASSEMBLY.
(LY20701)
BOTTOM CASE ASSEMBLY
PARTS NO.
LY20701
Fig.4-4-1
NOTE:
• Unless otherwise specified, all measurement points and ad-
justment parts are located on E. VF BOARD ASSEMBLY.
• After adjustment or replacement of the deflection yoke or the
centering magnet, fix it by the band as shown the figure below.
TOP VIEW
CRT
Fig.4-4-2
• After adjustment is completed, compare the picture on the E.
VF screen with the monitor TV.
CRT
Fig.4-4-3
VR7003
FOCUS
CN7002
VR7001
CN7001
V. SIZE
Fig.4-4-4
SERIAL NO. LABEL
SCREW
CENTERING
MAGNET
STOPPER
CENTERING
MAGNET
STOPPER
F.B.T
T7001
VR7002
BRIGHT
(No.YF016)1-19