JVC HR-J3008UM User manual

SERVICE MANUAL
No.82852
April 2001
HR-J3008UM/J4008UM
VIDEO CASSETTE RECORDER
Regarding service information other than these sections, refer to the HR-A37U service manual (No.82836).
Also, be sure to note important safety precautions provided in the service manual.
SPECIFICATIONS (The specifications shown pertain specifically to the model HR-J4008UM)
Specifications shown are for SP mode unless specified otherwise.
E. & O.E. Design and specifications subject to change without
notice.
GENERAL
Power requirement : AC 110 V – 220 Vd, 50 Hz/60 Hz
Power consumption
Power on : 14 W
Power off : 2.0 W
Temperature
Operating : 5°C to 40°C
Storage : –20°C to 60°C
Operating position : Horizontal only
Dimensions (W x H x D) : 360 mm x 94 mm x 247 mm
Weight : 3.0 kg
Format : VHS NTSC standard
Maximum recording time
SP : 210 min. with ST-210 video cassette
EP : 630 min. with ST-210 video cassette
VIDEO/AUDIO
Signal system : NTSC-type color signal and EIA
monochrome signal, 525 lines/
60 fields
Recording/Playback
system : DA-4 (Double Azimuth) head helical scan system
Signal-to-noise ratio : 45 dB
Horizontal resolution : 230 lines
Frequency range : 70 Hz to 10,000 Hz
Input/Output : RCA connectors (IN x 1, OUT x 1)
TUNER
Tuning system : Frequency-synthesized tuner
Channel coverage
VHF : Channels 2–13
UHF : Channels 14–69
CATV : 113 Channels
RF output : Channel 3 or 4 (switchable; preset to
Channel 3 when shipped) 75 ohms,
unbalanced
TIMER
Clock reference : Quartz
Program capacity : 1-year programmable timer/
8 programs
Memory backup time : Approx. 6 months
Estimated figure based on supplied
fresh battery; actual performance may
differ.
ACCESSORIES
Provided accessories : RF cable (F-type),
Lithium battery CR2025,
Infrared remote control unit,
“AA” battery x 2,
Conversion plug

TABLE OF CONTENTS
Section Title Page Section Title Page
DIFFERENT TABLE ........................................................................... 1 to 2
2. MECHANISM ADJUSTMENT
2.1 Before starting repair and adjustment...........................................2-1
2.1.1Precautions ...................................................................................2-1
2.1.2Checking for proper mechanical operations .................................2-1
2.1.3Manually removing the cassette tape ...........................................2-1
2.1.4Jigs and tools required for adjustment ..........................................2-2
2.1.5Maintenance and inspection .........................................................2-3
2.2 Replacement of major parts..........................................................2-6
2.2.1Before starting disassembling
(Phase matching between mechanical parts) .........................2-6
2.2.2How to set the “Mechanism assembling mode” ............................2-6
2.2.3Cassette holder assembly ............................................................2-6
2.2.4Pinch roller arm assembly ............................................................2-8
2.2.5Guide arm assembly and press lever assembly ...........................2-8
2.2.6A/C head .......................................................................................2-8
2.2.7Loading motor ...............................................................................2-8
2.2.8Capstan motor ..............................................................................2-9
2.2.9Pole base assembly (supply or take-up side) ...............................2-9
2.2.10 Rotary encoder .....................................................................2-10
2.2.11 Clutch unit .............................................................................2-10
2.2.12 Change lever assembly,direct gear,clutch gear
and coupling gear .................................................................2-10
2.2.13 Link lever...............................................................................2-11
2.2.14 Cassette gear,control cam and worm gear ........................... 2-11
2.2.15 Control plate..........................................................................2-11
2.2.16 Loading arm gear (supply or take-up side)
and loading arm gear shaft ...................................................2-12
2.2.17 Take-up lever,take-up head and control plate guide .............2-13
2.2.18 Capstan brake assembly ......................................................2-13
2.2.19 Sub brake assembly (take-up side) ......................................2-13
2.2.20 Main brake assembly (take-up side),
reel disk (take-up side) and
main brake assembly (supply side).......................................2-13
2.2.21 Tension brake assembly, reel disk (supply side)
and tension arm assembly ....................................................2-14
2.2.22 Idler lever, idler arm assembly ..............................................2-14
2.2.23 Stator assembly ....................................................................2-14
2.2.24 Rotor assembly .....................................................................2-14
2.2.25 Upper drum assembly...........................................................2-15
2.3 Compatibility adjustment.............................................................2-16
2.3.1FM waveform linearity.................................................................2-16
2.3.2Height and tilt of the A/C head ....................................................2-17
2.3.3A/C head phase (X-value) ..........................................................2-17
2.3.4Standard tracking preset.............................................................2-18
2.3.5Tension pole position ..................................................................2-18
4. CHARTS AND DIAGRAMS
4.1 MAIN (SYSCOM) AND LT BATTERY
SCHEMATIC DIAGRAMS .......................................................4-1
4.2 MAIN CIRCUIT BOARD
(MAIN PWB LPB10130-001C) [HR-J4008UM].............................4-3
4.3 MAIN CIRCUIT BOARD
(MAIN PWB LPB10130-001D) [HR-J3008UM].............................4-5
5. PARTS LIST
5.1 PACKING AND ACCESSORY ASSEMBLY <M1> ........................5-1
5.2 FINALASSEMBLY <M2>..............................................................5-2
5.3 MECHANISM ASSEMBLY <M4> ..................................................5-4
5.4 ELECTRICAL PARTS LIST ..........................................................5-6
MAIN BOARD ASSEMBLY <03> ..................................................5-6
A/C HEAD BOARD ASSEMBLY <12>. .......................................5-10
LOADING MOTOR BOARDASSEMBLY <55> ..........................5-10
LT BATTERY BOARDASSEMBLY <93>
[HR-J4008UM] .......................................................................510
The following table indicate main different points between models HR-A37U,HR-J3008UM and HR-J4008UM.
PACKING AND ACCESSORY ASSEMBLY <M1>
REF
NO.
!MODEL HR-A37U HR-J3008UM
ITEM
301 PACKING CASE LP30836-006A LP30836-017A LP30836-015B
306 REMOTE CONTROL UNIT LP20878-001A LP20878-002A
306A COVER(BATTERY) LP40610-001A LP40610-002A
!309 LITHIUM BATTERY ––– ––– PECA0903
!310 INST. BOOK(EN) LPT0497-001A ––– LPT0533-001A
!310 INST. BOOK(SP) ––– LPT0532-001A LPT0533-002A
311 POLY BAG ––– QPC02503530P
!313 CONVERSION PLUG ––– ––– PEMC1012
317 REGIST. CARD BT-51020-2 ––– –––
320 CONNECTION SHEET ––– PU36560-2
HR-J4008UM
Note: Mark is same as left.
1
The following table indicate main different points between models HR-A37U,HR-J3008UM and HR-J4008UM.
MODEL HR-A37U HR-J3008UM
ITEM
POWER VOLTAGE 120V, 60HZ110-220V, 50/60HZ
POWER PLUG UL, CSA SASO
COSMETIC/COLOR MOLD-DARK GRAY PAINT-Pure SILVER
RCU TYPE / COLOR U1 / MOLD BLACK E1 / PAINT SILVER
INSTRUCTION / LANGUAGE 1 SHEET / ENG YES / SPA YES / SPA, ENG
PLUG ADAPTER NOT USED SASO CEE
LITHIUM BATTERY NOT USED CR2025
HEAD CLEANER NOT USED USED
SHUTTLE SERCH(LATCH) SPX7, EPX21 SPX7, EPX21(X21)
B.E.S.T. PICTURE AUTO PICTURE A.V. CALIBRATION
AUTO CH PRESET USED (P&P) USED
BACKUP TIME NOT USED 6 MONTHS(LI BATT.)
TIMER PROGRAM BACKUP
PERMANENT PROGRAM NOT USED
SUMMER TIME ADJUST USED NOT USED
AUTO CLOCK / JUST CLOCK USED NOT USED
REC RESUME NOT USED USED
LANGUAGE[INITIAL] [ENG], SPA, FRE [SPA], ENG
HR-J4008UM
Note: Mark ––– is not used.
Mark is same as left.

2
FINAL ASSEMBLY<M2>
REF
NO.
!MODEL HR-A37U HR-J3008UM
ITEM
!501 FRONT PANELASSEMBLY * LP10348-004D LP10348-009F LP10348-008F
501A CASSETTE DOOR * LP20977-002C LP20977-008C
501C DISPLAY WINDOW LP20976-004A LP20976-009A LP20976-008A
!502 TOP COVER LP10352-002A LP10352-008A
503 SCREW,X2,TOP COVER(SIDE) QYTDSF3010M QYTDSF3010R
!511 BOTTOM CHASSIS * LP10350-003D LP10350-004D LP10350-005D
!517 POWER CORD ––– ––– QMP73J0-170
518 CLEANER ASSEMBLY ––– ––– LP40369-001D
518A CLEANER ROLLER ––– ––– PQ46418-1-2
518B CLEANER ––– ––– PQ46419-1-2
518C CLEANER ARM ––– ––– LP30407-001D
520 CAP ––– ––– LP30336-001A
531 SCREW,REAR ––– ––– QYTDSF3010M
532 SCREW,TERMINAL BOARD ––– ––– QYTDSF3010Z
HR-J4008UM
Note : Mark ––– is not used.
Mark is same as left.
Mark *reference model was also changed.
MAIN BOARD ASSEMBLY<03>
REF
NO.
!MODEL HR-A37U HR-J3008UM
ITEM
PW1 MAIN BOARD ASSEMBLY * LPA10130-02D1 LPA10130-05B1
HR-J4008UM
LITHIUM BATTERY BOARD ASSEMBLY<93>
REF
NO.
!MODEL HR-A37U HR-J3008UM
ITEM
!PW4 LITHIUM BATTERY BOARD ASSEMBLY ––– ––– LPA10130-01A4
HR-J4008UM

2-1
SECTION 2
MECHANISM ADJUSTMENT
2.1 Before starting repair and adjustment
2.1.1 Precautions
(1) Unplug the power cord plug of the VCR before using your
soldering iron.
(2) Take care not to cause any damage to the conductor
wires when plugging and unplugging the connectors.
(3) Do not randomly handle the parts without identifying
where the trouble is.
(4) Exercise enough care not to damage the lugs, etc. dur-
ing the repair work.
(5) When reattaching the front panel assembly, make sure
that the door opener of the cassette holder assembly is
lowered in position prior to the reinstallation. (See SEC-
TION 1 DISASSEMBLY.)
(6) When using the Jig RCU, it is required to set the VCR to
the Jig RCU mode (the mode in which codes from the
Jig RCU can be received). (See SECTION 1 DISASSEM-
BLY.)
2.1.2 Checking for proper mechanical operations
Enter the mechanism service mode when you want to oper-
ate the mechanism when no cassette is loaded. (See SEC-
TION 1 DISASSEMBLY.)
2.1.3 Manually removing the cassette tape
1. In case of electrical failures
If you cannot remove the cassette tape which is loaded be-
cause of any electrical failure, manually remove it by taking
the following steps.
(1) Unplug the power cord plug from the power outlet.
(2) Refer to the disassembly procedure and perform the dis-
assembly of the major parts before removing the drum
assembly.
(3) Unload the pole base assembly by manually turning the
loading motor of the mechanism assembly toward the
front. In doing so, hold the tape by the hand to keep the
slack away from any grease. (See Fig.2-1-3a.)
(4) Bring the pole base assembly to a pause when it reaches
the position where it is hidden behind the cassette tape.
(5) Move the top guide toward the drum while holding down
the lug (A) of the bracket retaining the top guide. Like-
wise hold part (B) down and remove the top guide.
Section (C) of the top guide is then brought under the
cassette lid. Then remove the top guide by pressing the
whole cassette tape down. (See Fig.2-1-3b.)
(6) Remove the cassette tape by holding both the slackened
tape and the cassette lid.
(7) Take up the slack of the tape into the cassette. This com-
pletes removal of the cassette tape.
Note:
• For the disassembly procedure of the major parts and
details of the precautions to be taken, see “SECTION
1 DISASSEMBLY”.
Fig. 2-1-3b
Fig. 2-1-3a
Loading motor
Pole base assembly
Press
(C)
(A)
(B)

2-2
2. In case of mechanical failure
If you cannot remove the cassette tape which is loaded be-
cause of any mechanical failure, manually remove it by tak-
ing the following steps.
(1) Unplug the power cable and remove the top cover, front
panel assembly and others so that the mechanism as-
sembly is visible. (See SECTION 1 DASASSEMBLY.)
(2) While keeping the tension arm assembly of the mecha-
nism assembly free from tension, pull the tape on the pole
base assembly (supply or take-up side) out of the guide
roller. (See Fig.2-1-3c.)
(3) Take the spring of the pinch roller arm assembly off the
hook of the press lever assembly, and detach it from the
tape. (See Fig.2-1-3d.)
(4) In the same way as in the electrical failure instructions in
2.1.3-1(5), remove the top guide.
(5) Raise the cassette tape cover. By keeping it in that posi-
tion, draw out the cassette tape case from the cassette
holder and take out the tape.
(6) By hanging the pinch roller arm assembly spring back
on the hook, take up the slack of the tape into the cas-
sette.
Fig. 2-1-3d
Fig. 2-1-3c
Pole base assembly (take-up side)
Pole base assembly
(supply side)
Tension arm assembly
Guide pole guard
Pinch roller arm assembly
Press lever assembly
Take the spring
off the hook, and
detach it from the
tape.
2.1.4 Jigs and tools required for adjustment
Roller driver
PTU94002 A/C head positioning tool PTU94010
Back tension cassette gauge
PUJ48076-2 Jig RCU
PTU94023B
Torque gauge
PUJ48075-2
Alignment tape
(SP, stairstep, NTSC)
MHP
Alignment tape
(EP, stairstep, NTSC)
MHP-L

2-3
2.1.5 Maintenance and inspection
1. Location of major mechanical parts
In this chapter, the two mechanism speeds are described by comparing the speeds of the standard type and the high-speed
FF/REW type.
It is possible to distinguish between these two types of mechanism by the diameters of their capstan pulleys.
The capstan pulley diameter for the standard type is approx. 32 mm.
The capstan pulley diameter for the high-speed FF/REW type is approx. 43 mm.
For information on the different parts used in the two mechanism types, please refer to the “Replacement of major parts”.
Fig. 2-1-5a Mechanism assembly top side
Stator assembly
UV catcher2 (supply and take-up side)
Drum assembly Head base
A/C head
Loading motor
Pinch roller arm
assembly
Guide pole guard
Press lever
assembly
Lid guide
Guide arm
assembly
Reel disk
(take-up side)
Sub brake assembly
(take-up side)
Main brake assembly
(take-up side)
Idler arm assembly
Idler lever
Main brake assembly
(supply side)
Reel disk
(supply side)
Rec safety lever
Tension brake
assembly
Adjust pin
Tension arm
assembly
Pole base assembly
(supply side)
Full erase head
Pole base assembly (take-up side)
T1
T26
T25
T24
T23
T22
T2 T3 T5 T7
T8
T9
T10
T11
T12
T13
T14
T15
T16T18
T20
T17T19T21
T6
Fig. 2-1-5b Mechanism assembly bottom side
Belt
(loading motor)
Capstan motor
Belt (capstan)
Capstan brake assembly
Loading arm gear (take-up side)
Loading arm gear (supply side)
Plate
(supply side)
Control plate
Worm gear
Control cam
Cassette gear
Rotary encoder
Change lever assembly Clutch unit
Take-up lever
Take-up head
Control
bracket1
Tension arm
bearing
B1
B22
B3 B5
B6
B7
B8
B9
B10
B12
B15
Rotary encoder guide
B16
B17
B18
Brake lever
B19
B20
B21
B14
B11
B4
B2
Direct gear
B13
Link lever

2-4
Guide rail Roller cam assembly
L2L1
Opener guide
Door
opener
Drive gear
Cassette housing bracket
Limit gear
Worm gear
Belt (loading motor)
Loading motor
R2
R3 R5
R4
R1
Fig. 2-1-5c Mechanism assembly left side
Fig. 2-1-5d Mechanism assembly right side
5. Disassembling procedure table
The following table indicates the order in which parts are re-
moved for replacement. To replace parts, remove them in
the order of 1 to 18 as shown in the table. To install them,
reverse the removal sequence.
The symbols and numbers preceding the individual part
names represent the numbers in the “Location of major me-
chanical parts” table. Also, the “T”, “B”, and “T/B” on the right
of each part name shows that the particular part is removed
from the front, from the back, and from both sides of the
mechanism, respectively.
2. Cleaning
Regular cleaning of the transport system parts is desirable
but practically impossible. So make it a rule to carry out clean-
ing of the tape transport system whenever the machine is
serviced.
When the video head, tape guide and/or brush get soiled,
the playback picture may appear inferior or at worst disap-
pear, resulting in possible tape damage.
(1) When cleaning the upper drum (especially the video
head), soak a piece of closely woven cloth or Kimu-wipe
with alcohol and while holding the cloth onto the upper
drum by the fingers, turn the upper drum
counterclockwise.
Note:
• Absolutely avoid sweeping the upper drum vertically
as this will cause damage to the video head.
(2) To clean the parts of the tape transport system other than
the upper drum, use a piece of closely woven cloth or a
cotton swab soaked with alcohol.
(3) After cleaning, make sure that the cleaned parts are com-
pletely dry before using the video tape.
3. Lubrication
With no need for periodical lubrication, you have only to lu-
bricate new parts after replacement. If any oil or grease on
contact parts is soiled, wipe it off and newly lubricate the
parts.
Note:
• See the “mechanism assembly” diagram of the parts
list for the lubricating or greasing spots, and for the
types of oil or grease to be used.
~1000H ~2000H
Upper drum assembly ¤R R
A/C head ¤R ¤R
Lower drum assembly
¤¤R
Pinch roller arm assembly ¤¤
Full erase head ¤¤
Tension arm assembly ¤¤
Capstan motor (Shaft) ¤¤
Guide arm assembly ¤¤
Capstan motor R
Capstan brake assembly R
Main brake assembly R
Belt (Capstan) RR
Belt (Loading motor) R
Loading motor R
Clutch unit R
Worm gear R
Control plate R
Brush ¤R ¤R
Tension brake assembly RR
Rotary encoder R
4. Suggested servicing schedule for main components
The following table indicates the suggested period for such
service measures as cleaning,lubrication and replacement.
In practice, the indicated periods will vary widely according
to environmental and usage conditions.However, the indi-
cated components should be inspected when a set is brought
for service and the maintenance work performed if neces-
sary. Also note that rubber parts may deform in time,even if
the set is not used.
Operation Hours
System Parts Name
¤: Cleaning
R: Inspection or replacement if necessary
Table 2-1-5a
Other Drive Tape transport

2-5
Symbols and numbers
Symbols and numbers Number of removal steps Guide rail Roller cam assembly Cassette housing bracket Opener guide Relay gear Cassette holder assembly Drive gear Drive arm Pinch roller arm assembly Guide arm assembly Press lever assembly UV catcher2 Rotary encoder Clutch unit Change lever assembly Direct gear Clutch gear Link lever Worm gear Control bracket1 Control plate Loading arm gear (supply side) Loading arm gear (take-up side) Take-up lever Sub brake assembly (take-up side) Main brake assembly (take-up side) Reel disk (take-up side) Tension brake assembly Tension arm assembly Idler lever Brake lever
(
*1
)
Front (T)/Back (B) of mechanism
(Reference items)
Replacement parts
Removal parts
L1
L1
L2
L2
R4
R1
R2
R5
R3
T9
T12
T11
T6
T7
B1
T1
T17
T10
T14
T15
T19
T13
T22
T20
T24
B9
T18
T16
B19
B16
B7
B8
B5
B4
B3
B11
B10
T25
B15
B12
B14
B13
B17
B18
B20
B21
R4 R1 R3 T9 T12 T11 B15 B12 B14 B13 B17 B21 B7 B8 B5 B4 B11 T14 T15 T13 T22 T24 T18 B19
T1
2.2.3 Guide rail T 1
2.2.3 Roller cam assembly T 1
2.2.3 Cassette housing bracket T 1
2.2.3 Opener guide T 2
2.2.3 Door opener T 3
2.2.3 Relay gear T 3
2.2.3 Limit gear T 3
2.2.3 Cassette holder assembly T 6
2.2.3 Drive gear T 4
2.2.3 Drive arm T 8
2.2.4 Pinch roller arm assembly T 1
2.2.5 Guide arm assembly T 1
2.2.5 Press lever assembly T 3
2.2.6 A/C head T 1
2.2.7 Loading motor T 1
2.2.8 Capstan motor T/B 1
2.2.9 UV catcher2 T 1
2.2.9
Pole base assembly (take-up side) T/B 2
2.2.9
Pole base assembly (supply side) T/B 2
2.2.10 Rotary encoder B 1
2.2.11 Clutch unit B 1
2.2.12 Change lever assembly B 3
2.2.12 Direct gear B 4
2.2.12 Coupling gear B 5
2.2.12 Clutch gear B 6
2.2.13 Link lever B 1
2.2.14 Cassette gear B 2
2.2.14 Control cam B 2
2.2.14 Worm gear B 1
- Lid guide T/B 5
2.2.15Control bracket1 B 1
2.2.15Control plate B 6
2.2.16Loading arm gear (supply side) B 7
2.2.16
Loading arm gear (take-up side) B8
2.2.16Loading arm gear shaft B 9
2.2.17Take-up lever T/B 7
2.2.17Take-up head T/B 8
2.2.17Control plate guide T/B 8
2.2.18Capstan brake assembly T/B 7
2.2.19
Sub brake assembly(take-up side) T/B 15
2.2.20
Main brake assembly(take-up side) T/B 16
2.2.20
Main brake assembly(supply side) T/B 9
2.2.20Reel disk (take-up side) T/B 16
2.2.21Tension brake assembly T/B 9
2.2.21Reel disk (supply side) T/B 10
2.2.21Tension arm assembly T/B 10
2.2.21Tension arm bearing T/B 10
2.2.22Idler lever T/B 17
2.2.22Idler arm assembly T/B 18
- Brake lever (
*1
) T/B 18
- Rotary encoder guide T/B 19 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
1 2 3 4 5 6 7 8 9
1 2 3 4 5 6 7 8 9
1 2 3 4 5 6 7 8 9
1 2 3 4 5 6 7 8
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
1 2 3 4 5 6 7 8
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
1 2 3 4
12
12
3
12
1
1
1
2 3 4
1 2 3 4 5
5 6 1 2 3 4 5 6
1 2 3 4 5 6
7
12
12
12
1
12
3
12 3
4 5
1 2 3 4 5
6 7
7
1 2 3 4 5 6
1 2 3 4 5 6
1 2 3 4 5 6 7
1 2 3 4 5 6
1 2 3 4 5
1 2 3 4
1
1
1
2
3 4
5
6
7
8
7
8
9 10 11 12 13 14
Table 2-1-5b
Note:
• The parts with marked (
*
)have different types of mecha-
nisms (standard type or high-speed FF/REW type).
*
1: Uses the standard type mechanism only.
*
2:Uses the high-speed FF/REW type mechanism only.

2-6
(4) While swinging the lock levers (R) and (L) of the cassette
holder assembly toward the front, slide the cassette
holder assembly until its legs come to where the guide
rail and the roller cam assembly have been removed (so
that the drive arm is upright). (See Fig.2-2-3c.)
Fig. 2-2-3c
Cassette holder assembly
Lock lever (L) Drive arm
(Upright)
Leg Legs
2.2.3 Cassette holder assembly
1. How to remove
(1) Remove the guide rail and roller cam assembly. (See
Fig.2-2-3a.)
(3 lugs on the guide rail and one lug on the roller cam
assembly)
Fig. 2-2-2a
Worm gear
Guide hole
Control cam
Chassis hole
Control plate
Mark E
Fig. 2-2-3b
(2) Remove the two slit washers and remove the cassette
housing bracket. (See Fig.2-2-3b.)
(3) Remove the opener guide, spring(A), door opener, relay
gear and limit gear. (See Fig.2-2-3b.)
Fig. 2-2-3a
Lugs Lug
Lug
Guide rail
Roller cam
assembly
Limit gear
Relay gear
Opener guide
Spring(A)
Cassette housing bracket
Slit washers
Door opener
2.2 Replacement of major parts
2.2.1 Before starting disassembling (Phase matching
between mechanical parts)
The mechanism of this unit is closely linked with the rotary
encoder and system controller circuits.
Since the system controller detects the status of mechani-
cal operation in response to phases of the rotary encoder
(internal switch positions), the mechanism may not operate
properly unless such parts as the rotary encoder, control
plate, loading arm gear, control cam, cassette gear, limit gear,
relay gear and drive gear are installed in their correct posi-
tions.
Especially, this model is not provided with any cassette hous-
ing assembly, so that cassette loading and unloading must
be accomplished by operation of the cassette holder assem-
bly. The latter is in turn driven by such parts as the drive
gear, relay gear and limit gear. Exercise enough care, there-
fore, to have the phases of all this gear matching one an-
other. (For information on phase matching of the mechanism,
see the instructions on how to install individual parts.)
This unit is provided with a mechanism assembly mode. It is
therefore necessary to enter this mode for assembling and
disassembling procedures.
This mode is usually not in use, manually set it when it is
required.
2.2.2 How to set the “Mechanism assembling mode”
Remove the mechanism assembly and place it bottom side
up. (See SECTION 1 DISASSEMBLY.) Turn the worm gear
toward the front so that the guide hole of the control cam is
brought into alignment with the hole at the mechanism as-
sembly chassis. This position renders the mechanism assem-
bling mode operational. Make sure that the control plate is
located in alignment with the mark E. (See Fig.2-2-2a.)

2-7
Fig. 2-2-3d
(5)
While holding the left side of the cassette holder, lift the
cassette holder assembly so that the three legs on the
left side are all released. Then pull the legs (A) and (B)
on the right side out of the rail and also pull up the leg(C).
(See Fig.2-2-3d and Fig.2-2-3e.)
(6) Draw out the drive gear, and remove the drive arm.
Fig. 2-2-3e
Cassette holder assembly
Cassette holder assembly
(A)
(C) (B)
Fig. 2-2-3f
Hole
Hole
Drive arm
Drive gear
Drive arm
(1) (2)
(A)
(B)
Main deck right side Fig. 2-2-3g
2. How to install (Phase matching)
(1) Insert the section (A) of the drive arm into the section (B)
of the main deck.
(2) Insert the section (1) of the drive gear into the round hole,
and the section (2) into the square hole on the drive arm.
(See Fig.2-2-3f.)
(3) Hold the drive arm upright and fit the leg (C) on the right
side of the cassette holder assembly into the groove. (See
Fig.2-2-3g.)
(4) While swinging the lock lever (R) of the cassette holder
assembly toward the front, put the legs (A) and (B) into
the rail. (See Fig.2-2-3g.)
(5) Drop the three legs on the left side of the cassette holder
assembly into the groove at one time. (See Fig.2-2-3h.)
(6) Slide the whole cassette holder assembly toward the front
to bring it to the eject end position.
(7) Install the limit gear so that the notch on the outer cir-
cumference of the limit gear is brought into alignment with
the guide hole on the main deck. (See Fig.2-2-3i.)
(8) Install so that the notch on the periphery of the relay gear
is aligned with the notch of the main deck and that hole
A of the relay gear is aligned with the hole A of the limit
gear and that hole B of the relay gear is aligned with the
hole B of the drive gear. (See Fig.2-2-3i.)
(9) Install the door opener, opener guide, spring(A) and cas-
sette housing bracket and fasten the two slit washers.
Cassette holder assembly
Drive arm
Lock lever (R)
(A)
(C) (B)
Fig. 2-2-3h
Cassette holder assembly

2-8
2.2.7 Loading motor
1. How to remove
(1) Remove the belt wound around the worm gear.
(2) Open the two lugs of the motor guide and remove the
loading motor, loading motor board assembly and motor
guide altogether by pulling them up.
(3) When replacing the loading motor board assembly, take
care with the orientation of the loading motor. (Install so
that the loading motor label faces upward.)
(4) When the motor pulley has been replaced, choose the
fitting dimension as indicated in Fig.2-2-7a.
2.2.4 Pinch roller arm assembly
1. How to remove
(1) Remove the spring from the hook of the press lever as-
sembly.
(2) Remove the slit washer and remove the pinch roller seat
2. (See Fig.2-2-4a.)
(3) Remove the pinch roller arm assembly by pulling it up.
Fig. 2-2-5a
2.2.6 A/C head
1. How to remove
(1) Remove the two screws (A) and remove the A/C head
together with the head base.
(2) When replacing only the A/C head, remove the three
screws (B) while controlling the compression spring.
Fig. 2-2-6a
Fig. 2-2-6c
Fig. 2-2-4a
2.2.5 Guide arm assembly and press lever assembly
1. How to remove
(1) Remove the spring and expand the lug of the lid guide in
the arrow-indicated direction. Then remove the guide arm
assembly by pulling it up.
(2) Remove the press lever assembly by pulling it up. (See
Fig.2-2-5a.)
Tension
spring
Press lever
assembly
Guide arm
assembly
LugLid guide
Head base
Screws(A)
A/C head
Compression
springs
Head base
A/C head board
assembly
A/C head
Screws(B)
Fig. 2-2-6b
2. How to install
(1) To make the post-installation adjustment easier, set the
temporary level as indicated in Fig.2-2-6c. Also make sure
that the screw center (centre) is brought into alignment
with the center (centre) position of the slot.
Head base
Head base
Screw
A/C head
A/C head
12.4 mm
Pinch roller seat2
Pinch roller arm
assembly
Pinch roller arm assembly
Slit washer
Spring
Press lever assembly
Fig. 2-2-3i
Relay gear
Drive gear Limit gear
Guide holeNotches Notch
B
AA
B

2-9
Fig. 2-2-8b
Loading motor board assembly
Loading motor
Motor guide
Worm gear
Belt
Lugs
6.5 ±0.2 mm
Motor pulley
LABEL
Fig. 2-2-7a
Fig. 2-2-8a
2.2.8 Capstan motor
1. How to remove
(1) Remove the belt (capstan) on the mechanism assembly
back side.
(2) Remove the three screws (A) and remove the capstan
motor.
Capstan motor
Belt
Screw(A)
Screws(A)
2. How to install (Centering the mounting position)
When the capstan motor has once been removed and then
reinstalled out of the initial correct position in the rotational
direction, the capstan motor current may be unstable during
operation in high or low temperatures. This may result in
greater Wow & Flutter and occasionally in power breakdown
because of current over - load. Install the capstan motor while
following the procedure given below.
(The capstan motor is centrally located when the unit is
shipped from the factory.)
(1) Provisionally tighten the three screws (A) securing the
capstan motor.
(2) Install the mechanism assembly to which the capstan
motor is provisionally fastened on the bottom chassis
which incorporates the Main board assembly. (No need
to tighten the screws for mounting the mechanism.)
Make sure that all the connectors for the mechanism as-
sembly and the Main board assembly are correctly in-
stalled as indicated in Fig. 2-2-8b.
(3) Making sure that the connector for the capstan motor is
correctly mounted, and securely tighten the three screws
(A).
Note:
• When the capstan motor has been replaced with a new
one, perform recording in the EP(or LP) mode for at
least 2 minutes at normal temperatures immediately be-
fore starting the FF/REW or SEARCH operations (Ag-
ing).
Spacer Spacer
Connector for
the capstan motor
2.2.9 Pole base assembly (supply or take-up side)
1. How to remove
(1) Remove the UV catcher 2 on the removal side by loos-
ening the screw (A).
(2) Remove the pole base assembly on the supply side from
the mechanism assembly by loosening the screw (B) on
the mechanism assembly back side and sliding the pole
base assembly toward the UV catcher 2.
(3) As for the pole base assembly on the take-up side, turn
the pulley of the loading motor to lower the cassette
holder because the screw (B) is hidden under the con-
trol plate. (See the “Procedures for Lowering the Cassette
holder assembly” of 1.3 DISASSEMBLY/ASSEMBLY
METHOD.) Further turn the motor pulley to move the cas-
sette holder until the screw (B) is no longer under the con-
trol plate (in the half-loading position). Then remove it as
done for the supply side by removing the screw (B).
Note:
• After reinstalling the Pole base assembly and the UV
catcher2, be sure to perform compatibility adjustment.
Fig. 2-2-9a
Screw(B)
Screw(A)
UV catcher2
Screw(A)
UV catcher2

2-10
Fig. 2-2-11a
2. How to install
(1) Install the clutch gear, spring (A), spring (C), direct gear,
spacer and others to the individual shafts of the main
deck, and finally the slit washer. (See Fig.2-2-12a.)
(2) Let the spring (B) drops into the rotary encoder guide hole
and install the change lever assembly.(Take care not to
mistake a direction of the spring.) The point is to slightly
lift the clutch gear and catch it from the both sides with
the assembly. (See Fig.2-2-12b.)
Slit washer
Belt
Clutch unit
2.2.11 Clutch unit
(1) Remove the belt wound around the capstan motor and
the clutch unit.
(2) Remove the slit washer and remove the clutch unit.
Fig. 2-2-12b
Fig. 2-2-12a
Spacer
Change lever
assembly
Direct gear
Coupling gear
Spring (C)
Slit washer
Lugs
Spring(A)
Position the projecting
side down.
Spring(B)
Washer (
*
1)
Spacer
Clutch gear
Spring(B)
Rotary encoder guide
Main deck Main deck
Change lever assembly
Coupling gear
2.2.12 Change lever assembly, direct gear, clutch gear
and coupling gear
1. How to remove
(1) Release the two lugs of the rotary encoder guide in the
arrow-indicated direction and remove the change lever
assembly.
(2) Remove the slit washer retaining the direct gear and re-
move the latter.
Take care so as not to lose the washer and spring. (See
Fig.2-2-12a.)
2.2.10 Rotary encoder
1. How to remove
(1) Remove the screw (A) and remove the rotary encoder
by pulling it up. (See Fig. 2-2-10a.)
Fig. 2-2-10a
Rotary encoder (Front side)
Screw(A)
Rotary encoder (Back side)
Positioning pin of the rotary encoder
Guide marks
Fig. 2-2-10b
2. How to install (Phase matching)
(1) Make sure that the mark E of the control plate is in align-
ment with the mark of the loading arm gear shaft and
bring the guide marks on the rotary encoder into align-
ment as indicated in Fig.2-2-10a. (See Fig. 2-2-10a and
Fig. 2-2-10b.)
(2) Turn over the rotary encoder with its guide marks kept in
alignment and install it by fitting on the shaft of the rotary
encoder guide and the positioning pin.
(3) Tighten the screw (A) to complete the installation.
Control plate
Shaft of the rotary encoder guide
Mark E
Note:
• The parts with marked (*) have different types of mechanisms (standard type or high-
speed FF/REW type).
*1 : Uses the standard type mechanism only.
*2:
Uses the high-speed FF/REW type mechanism only.

2-11
Fig. 2-2-13a
Slit washers
Link lever
Locking section of the
control plate
2.2.13 Link lever
1. How to remove
(1) Remove the two slit washers.
(2) Remove the link lever by lifting it from the shaft retained
by the slit washers. Then swing the link lever
counterclockwise and remove it from the locking section
of the control plate.
Fig. 2-2-13b
2. How to install (Phase matching)
(1) Slide the control plate so that its mark E is aligned with
the mark on the loading arm gear shaft. (See Fig.2-2-
13b.)
(2) Rotate the worm gear until the guide hole of the control
cam is aligned exactly with the guide hole of the main
deck. (See Fig.2-2-13c.)
(3) Insert the link lever into the locking section of the control
plate. (See Fig.2-2-13a.)
(4) Rotate the link lever clockwise so that it is installed on
the shafts in the center (centre) and on the left of the con-
trol cam.
(5) Fasten the slit washers at these two points.
Control plate
Shaft of the rotary encoder guide
Mark E
Fig. 2-2-13c
Worm gear
Control cam
Main deck
guide hole
Control cam
guide hole
Cassette gear
2.2.14 Cassette gear, control cam and worm gear
1. How to remove
(1) Remove the control cam by lifting it.
(2) Open the two lugs of the cassette gear outward and pull
the latter off.
(3) Remove the belt wound around the worm gear and the
loading motor.
(4) Open the lug of the lid guide outward and remove the
worm gear.
Fig. 2-2-14a
2.2.15 Control plate
1. How to remove
(1) Remove the screw (A) retaining the control bracket 1 and
remove the latter.
(2) Slide the control plate as indicated by the arrow and re-
move the control plate. (See Fig.2-2-15a.)
Belt
Loading motor
Lug
Worm gear Lid guide
Lugs Cassette gear Control cam
Fig. 2-2-15a
Control
bracket1
Control
plate
Screw(A)
2. How to install (Phase matching)
(1) Adjust the position of the idler arm assembly pin as indi-
cated in Fig.2-2-15b (to the left of center (centre) of the
R section).
(2) Bring the guide hole of the take-up lever into alignment
with the hole at the control plate guide and fix the posi-
tion by inserting a 1.5 mm hexagonal wrench.

2-12
2. How to install
(1) Align the notch of the loading arm gear (take-up side) to
the projection B of the loading arm gear shaft and slip it
over. Then rotate it clockwise for alignment with the pro-
jection A and slip it down to the bottom. (See Fig.2-2-
16b.)
(2) Then turn the loading arm gear (take-up side)
counterclockwise. Hang the torsion arm on the pole base
assembly (take-up side) and tighten the screw (B).
(3) Install the loading arm gear (supply side) so that the guide
mark of the loading arm gear (take-up side) is in align-
ment with the guide mark of the loading arm gear (sup-
ply side). Then hang the torsion arm on the pole base
assembly (supply side) and tighten the screw (A). (See
Fig.2-2-16a.)
Fig. 2-2-16b
Projection A Loading arm gear shaft
Loading arm gear (take-up side)
Projection B
Fig. 2-2-15b
Idler arm assembly
pin Take-up lever
Insert
R section
Guide hole of the
control plate guide
1.5mm hexagonal wrench
2.2.16 Loading arm gear (supply or take-up side) and
loading arm gear shaft
1. How to remove
(1) Remove the loading arm gear (supply side) by loosen-
ing the screw (A). (See Fig. 2-2-16a.)
(2) Remove the screw (B) and remove the torsion arm from
the pole base assembly (take-up side). (See Fig.2-2-16a.)
Fig. 2-2-15c
Section A
Hole A
Section B
Hole B
Section C Control plate
Pole base assembly
(supply side)
Press-
fit
Section B
Hole B
Section C Tension arm assembly
shaft
Section D Section D
Section A
Hole A
(3) Install the control plate so that the section A of the load-
ing arm gear shaft fits into the hole (A) of the control plate,
the section B of the control plate guide into the hole (B),
and the control plate comes under the section C of the
rotary encoder guide and the section D of the loading arm
gear shaft while press-fit the pole base assmebly (sup-
ply side) as indicated by the arrow. It is important that
the tension arm assembly shaft is positioned closer to-
ward you than the control plate. (See Fig.2-2-15c.)
(4) Make sure that the mark E of the control plate is in align-
ment with the mark of the loading arm gear shaft. (See
Fig.2-2-15c.)
(5) Pull off the hexagonal wrench for positioning.
Fig. 2-2-16a
(3) Turn the loading arm gear (take-up side) clockwise so
that the notch of the loading arm gear (take-up side) is
in alignment with the projection of the loading arm gear
shaft and lift it.
Likewise, turn the loading arm counterclockwise so that
the notch is in alignment with the projection and remove
the loading arm gear (take-up side). (See Fig.2-2-16a and
Fig. 2-2-16b.)
(4) When removing the loading arm gear shaft, be sure of
first removing the screw retaining the drum assembly (on
the back side of the loading arm gear shaft). Then re-
move the screw (C) and remove the loading arm gear
shaft by sliding it.
Guide marks
Screw(A)
Screw(C)
Notch
Pole base assembly
(supply side)
Pole base assembly
(take-up side)
Screw(B)
Torsion arm
Loading arm gear
(take-up side) Loading arm gear (supply side) Loading arm gear shaft

2-13
2.2.17 Take-up lever, take-up head and control plate
guide
(1) Remove the spring of the take-up lever from the main
deck.
(2) Remove the lug (A) of the take-up lever from the main
deck and pull out the take-up lever and the take-up head
together.
(3) Remove the screw (A).
(4) Align the idler arm assembly pin in the center (centre) of
the R section of the control plate guide, remove the con-
trol plate guide lugs (B) and (C) from the main deck, and
remove the control plate guide.
Fig. 2-2-17a
Take-up head
Screw(A)
Lug(A)
Lug(B)
Control plate guide
Take-up lever
Lug(C)
Idler arm assembly pin
2.2.18 Capstan brake assembly
1. How to remove
(1) Move the lug (A) of the capstan brake assembly in the
arrow-indicated direction so that it comes into alignment
with the notch of the main deck. (See Fig. 2-2-18a.)
(2) Remove the lug (B) of the capstan brake assembly from
the main deck and remove the capstan brake assembly.
Fig. 2-2-18a
Capstan brake assembly
Lug(A)
Lug(B)
2.2.19 Sub brake assembly (take-up side)
1. How to remove
(1) Remove the spring attached to the lid guide and sub
brake assembly (take-up side).
(2) Bring the lug (A) of the sub brake assembly (take-up side)
into alignment with the notch of the main deck.
(3) Remove the lugs (B) and (C) of the sub brake assembly
(take-up side) from the main deck and remove the sub
brake assembly (take-up side).
Fig. 2-2-19a
Spring
Sub brake
assembly
(take-up side)
Lug(B)
Lug(A)
Lug(C)
Fig. 2-2-20a
Lug(D)
Lug(C) SpringLug(E)
Lug(A)
Lug(B)
Main brake assembly
(take-up side)
Reel disk
(take-up side)
Main brake assembly
(supply side)
Notch
2.2.20 Main brake assembly (take-up side), reel disk
(take-up side) and main brake assembly (supply
side)
1. How to remove
(1) Move the main brake assembly (take-up side) in the ar-
row-indicated direction and remove the reel disk (take-
up side).
(2)
Remove the spring attached to the main brake assembly.
(3) Remove the lug (A) of the main brake assembly (take-
up side) and pull out the lug (B) after bringing it into align-
ment with the main deck notch.
(4) Remove the lugs (C), (D) and (E) of the main brake as-
sembly (supply side) from the main deck and pull them
off. (See Fig.2-2-20a.)
(5) When installing the main brake assembly (take-up side),
slide the brake lever in the direction as indicated by the
arrow to prevent it from hitting the projection of the main
brake assembly (take-up side). (See Fig.2-2-20b.)
Fig. 2-2-20b
Projection of the main
brake assembly
(take-up side)
Rotary encoder guide
(
*
1)
Brake
lever
Note:
• The parts with marked (
*
) have different types of mechanisms (standard type
or high-speed FF/REW type).
*
1 : Uses the standard type mechanism only.

2-14
2.2.22 Idler lever, idler arm assembly
1. How to remove
(1) Remove the lug of the idler lever from the main deck and
remove the hook fitted in the idler arm assembly hole by
lifting it.
(2) Remove the slit washer and pull out the idler arm assem-
bly.
2.2.24 Rotor assembly
1. How to remove
(1) Remove the stator assembly.
(2) Remove the two screws (B) and remove the rotor assem-
bly.
2. How to install
(1) Match the phases of the upper drum assembly and the
rotor assembly as indicated in Fig.2-2-24a.
(2) Place the upper drum assembly hole (a) over the rotor
assembly holes (b) (with three holes to be aligned) and
tighten the two screws (B). (See Fig.2-2-24a.)
Lug Idler lever
Hook
Idler arm
assembly
Slit washer
Fig. 2-2-23a
Stator assembly Flat cable
(Take care not to mix up the
polar faces when installing.)
Lug wire
(Note)
Screw (A)
Screw (A)
Lug wire
Drum
shaft
Screw (B)
2.2.21 Tension brake assembly, reel disk (supply side)
and tension arm assembly
1. How to remove
(1) Remove the three lugs of the tension brake assembly
from the main deck and pull them off.
(2) Remove the reel disk (supply side) by loosening in the
arrow-indicated direction the main brake assembly (sup-
ply side).
(3) Remove the tension spring on the back of the main deck.
Then release the lug of the tension arm bearing in the
arrow-indicated direction and draw out the tension arm
assembly. (See Fig. 2-2-21a.)
Fig. 2-2-21a
Lugs
Tension brake
assembly
Lug of the tension
arm bearing Reel disk (supply side)
Tension arm
assembly
Tension spring Main brake assembly
(supply side)
Fig. 2-2-22a
Screws (B)
Rotor assembly
Hole(a)
Hole(b)
Screw holes
Upper drum
assembly The hole is not in
line but is offset
toward the right.
Fig. 2-2-24a
2.2.23 Stator assembly
(1) Remove the flat cable.
(2) Remove the two screws (A), (B) and remove the lug wire.
(3) Remove the stator assembly by lifting in the arrow-indi-
cated direction. (Take care that the brush spring does not
jump out.)
Notes:
• Be careful not to lose the brush and spring.
• There are some models that do not use the lug wire.
Refer to the parts list for these models.
• When tightening the screw (B), place the caulked part
of the lug terminal near to the shaft of the drum and
then tighten it.
• After installation, be sure to perform the switching
point adjustment according to the electrical adjustment
procedure.

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

2-16
Fig. 2-3-1a
Improper waveform variation
Max level Min level
Proper waveform variation
Fig. 2-3-1b
Roller driver
Guide roller (supply side)
2.3 Compatibility adjustment
Notes:
• Although compatibility adjustment is very important,
it is not necessary to perform this as part of the nor-
mal servicing work. It will be required when you have
replaced the A/C head, drum assembly or any part of
the tape transport system.
• To avoid any damage to the alignment tape while per-
forming the compatibility adjustment, get a separate
cassette tape (for recording and play back) ready to
be used for checking the initial tape running behavior.
• Unless otherwise specified, all measuring points and
adjustment parts are located on the Main board.
• When using the Jig RCU, it is required to set the VCR
to the Jig RCU mode (the mode in which codes from
the Jig RCU can be received). (See SECTION 1 DISAS-
SEMBLY.)
(1) Play back the alignment tape (A1).
(2) Apply the external trigger signal to D.FF (E), to observe
the V.PB FM waveform at the measuring point (D).
(3) Set the VCR to the manual tracking mode.
(4) Make sure that there is no significant level drop of the
V.PB FM waveform caused by the tracking operation, with
its generally parallel and linear variation ensured. Per-
form the following adjustments when required. (See Fig.
2-3-1a.)
(5) Reduce the V.PB FM waveform by the tracking opera-
tion. If a drop in level is found on the left side, turn the
guide roller of the pole base assembly (supply side) with
the roller driver to make the V.PB FM waveform linear.
If a drop in level is on the right side, likewise turn the guide
roller of the pole base assembly (take-up side) with the
roller driver to make it linear. (See Fig. 2-3-1c.)
(6) Make sure that the V.PB FM waveform varies in parallel
and linearly with the tracking operation again. When re-
quired, perform fine-adjustment of the guide roller of the
2.3.1 FM waveform linearity
Fig. 2-3a Jig RCU [PTU94023B]
pole base assembly (supply or take-up side).
(7) Unload the cassette tape once, play back the alignment
tape (A1) again and confirm the V.PB FM waveform.
(8) After adjustment, confirm that the tape wrinkling does not
occur at the roller upper or lower limits. (See Fig. 2-3-
1d.)
[Perform adjustment step (9) only for the models
equipped with SP mode and EP (or LP) mode.]
(9) Repeat steps (1) to (8) by using the alignment tape (A2).
INITIAL MODE
DATA CODE
CUSTOM CODE
43: A CODE
53: B CODE
[Data transmitting method]
Depress the “ ” ( 3 ) button
after the data code is set.
Jig RCU
Signal (A1) • Alignment tape(SP, stairstep, NTSC) [MHP]
(A2) • Alignment tape(EP, stairstep, NTSC) [MHP-L]
Mode (B) •PB
Equipment (C) •Oscilloscope
Measuring point (D) •TP106 (PB. FM)
External trigger (E) •TP111 (D.FF)
Adjustment part (F) •Guide roller [Mechanism assembly]
Specified value (G) •Flat V.PB FM waveform
Adjustment tool (H) •Roller driver [PTU94002]

2-17
Fig. 2-3-1d
(a) Guide roller
(b) Guide pole
Improper Proper
Fig. 2-3-1c
A
B
CD
Level drop at the guide roller (supply side)
Level drop at the guide roller (take-up side)
• Proper waveform variation: Always flat
• Improper waveform variation:
Higher Lower
2.3.2 Height and tilt of the A/C head
Note:
• Set a temporary level of the height of the A/C head in
advance to make the adjustment easier after the A/C
head has been replaced. (See Fig.2-2-6c.)
(2)
(3)
(1)
AUDIO OUT
Head base
A/C head
CTL. P
Fig. 2-3-2a
(1) Play back the alignment tape (A).
(2) Apply the external trigger signal to D.FF (E), to observe
the AUDIO OUT waveform and Control pulse waveform
at the measuring points (D1) and (D2) in the ALT mode.
(3) Set the VCR to the manual tracking mode.
Signal (A) • Alignment tape(SP, stairstep, NTSC) [MHP]
Mode (B) •PB
Equipment (C) •Oscilloscope
Measuring point (D1) •AUDIO OUT terminal
(D2) •TP4001 (CTL. P)
External trigger (E) •TP111 (D.FF)
Adjustment part (F) •A/C head [Mechanism assembly]
Specified value (G) •Maximum waveform
2.3.3 A/C head phase (X-value)
Signal (A1) • Alignment tape(SP, stairstep, NTSC) [MHP]
Mode (B) •PB
Equipment (C) •Oscilloscope
Measuring point (D) •TP106 (PB. FM)
External trigger (E) •TP111 (D.FF)
Adjustment part (F) • A/C head base [Mechanism assembly]
Specified value (G) •Maximum V.PB FM waveform
Adjustment tool (H) •A/C head positioning tool [PTU94010]
(1) Play back the alignment tape (A1).
(2) Apply the external trigger signal to D.FF (E), to observe
the V.PB FM waveform at the measuring point (D).
(3) Set the VCR to the manual tracking mode.
(4) Loosen the screws (4) and (5), then set the A/C head
positioning tool to the innermost projected part of the A/
C head. (See Fig. 2-3-3a.)
(5) Turn the A/C head positioning tool fully toward the cap-
stan. Then turn it back gradually toward the drum and
stop on the second peak point position of the V.PB FM
waveform output level. Then tighten the screws (4) and
(5).
(6) Perform the tracking operation and make sure that the
V.PB FM waveform is at its maximum.
If it is not at maximum, loosen the screws (4) and (5),
and turn the A/C head positioning tool to bring the A/C
head to a position, around where the waveform reaches
its maximum for the first time. Then tighten the screws
(4) and (5).
(4) Adjust the AUDIO OUT waveform and Control pulse
waveform by turning the screws (1), (2) and (3) little by
little until both waveforms reach maximum. The screw (1)
and (3) are for adjustment of tilt and the screw (2) for azi-
muth.