JVC HR-S9850EK, Service Manual

Page: 31 / 90

2-15
2.2.25 Upper drum assembly
Notes:
• To replace the upper drum assembly only may not be
possible with some models. For upper drum assem-
bly replacement, refer to the parts list. (When the parts
number of the upper drum assembly is not listed on
the parts list, then this cannot be replaced.)
• When replacement is required, control the up- down
movement of the brush. Never apply grease.
• When replacing the upper drum assembly, replace it
the together with the washer.
1. How to remove
(1) Remove the stator assembly and rotor assembly.
(2) Loosen the screw of the collar assembly using a 1.5 mm
hexagonal wrench and remove the collar assembly. Also
remove the brush, spring and cap at one time.
(3) Remove the upper drum assembly and remove the
washer using tweezers.
2. How to install
(1) Clean the coil parts of the lower drum assembly and the
newly installed upper drum assembly with an air brush
in advance. (See Fig.2-2-25b.)
(2) Install a new washer and upper drum assembly on the
drum shaft. (See Fig.2-2-25a.)
(3) Install the cap to the upper drum assembly.
(4) Position the collar assembly as indicated in Fig.2-2-25c
while controlling its up- down movement.
(5) Secure the collar assembly in position with a hexagonal
wrench while pressing its top with the fingers.
(6) After installation, gently turn the upper drum assembly
with your hand to make sure that it turns normally. Then
install the brush and the spring.
(7) Install the rotor assembly and stator assembly according
to Fig 2-2-23a and 2-2-24a.
(8) When installation is complete, clean the upper drum as-
sembly and lower drum assembly and carry out the fol-
lowing adjustments.
• PB switching point adjustment
• Slow tracking adjustment
• Compatibility adjustment (Be sure to check for compat-
ibility for the EP (or LP) mode.)
Fig. 2-2-25a
Fig. 2-2-25b
Spring
Brush
Cap
Upper drum
assembly
Washer
Lower drum assembly
Shaft
1.5 mm
hexagonal wrench
Loosen
Collar
assembly
Upper drum assembly
Coil parts
Lower drum assembly
Fig. 2-2-25c
Fig. 2-2-25d
Collar
assembly
Upper drum
assembly
Tighten
Collar
assembly
Press