Teac MV-8080G User manual

Service Manual
Video Cassette Recorder
NO.289C3090
MV-8080G
MV-8080G_1 Cover 97.12.10, 20:35Page 1 Adobe PageMaker 6.0J/PPC

Quick Reference of Specific Parts List
(Latest upgrade list Dec. ’97)
The parts No. of Deck Mechanisms, Face Plate Ass’y and Video Circuit Boards for MV-8080G.
CABINET & CHASSIS
Ref. No. Part No. Description
1 59311 UPPER DECK MECHANISM (TN6500-116M) FOR P.B. ONLY
2 59277 LOWER DECK MECHANISM (TN6500-105M) FOR REC/PB
21 22329340 FACE PLATE ASS’Y (MV-8080G)
32 26021610 POWER CORD
35R93C0 UPPER VIDEO CIRCUIT BOARD (MV-8080G)
36 MAIN CIRCUIT BOARD (WITH POWER SECTION)
(IC1701) (119412400) (IC,CXP88132-185Q)
37 HEAD CIRCUIT BOARD
38 SCART CIRCUIT BOARD
35R94C0 LOWER VIDEO CIRCUIT BOARD (MV-8080G) LOWER DECK
39 MAIN CIRCUIT BOARD (WITH TUNER)
(ET2A01) (104307420) (ET-TMLG1-103A)
(IC2701) (119413400) (IC,CXP87360-120Q)
(IC2703*) (113112B00) (IC,AT24C02-10PC)
40 HEAD CIRCUIT BOARD
For details, refer to pages 26 to last page.
*The IC ROM settings vary for each model, so please specify the model you are using when ordering replace-
ment IC-ROM 2703 parts.
ACCESSORIES
Ref. No. Part No. Description
1 1080738H0 REMOTE CONTROLLER, RC-738
2 28529280 IN-BOX MV-8080G
3 28939060 OWNER'S MANUAL KIT MV-8080G
MV-8080G_1_Cover2 97.12.10, 20:38Page 2 Adobe PageMaker 6.0J/PPC

1
CONTENTS
MAINTENANCE PRECAUTIONS.........................................................................2
ELECTRICAL ADJUSTMENT..............................................................................5
1. PLAYBACK SWITCHING POINT ADJUSTMENT .........................................................................................5
MECHANICAL ADJUSTMENT ............................................................................6
DECK ADJUSTMENT POINTS ...........................................................................................................................6
1. MECHANISM CONTROL ..............................................................................................................................7
2. ADJUSTMENT OF BT TORQUE IN PLAY MODE ........................................................................................8
3. AUDIO/CTL HEAD.........................................................................................................................................9
4. TAPE TRANSPORT SYSTEM CHECKS AND ADJUSTMENT.....................................................................9
5. INTERCHANGEABILITY ADJUSTMENT ....................................................................................................11
6. RG POST HEIGHT ADJUSTMENT ..............................................................................................................14
7. FRONT LOADING ASSEMBLY ATTACHMENT...........................................................................................15
PERIODIC MAINTENANCE ..............................................................................................................................16
SERVICING DIAGRAM AND PARTS LIST ....................................................... 18
1. EXPLODED VIEW OF THE CASSETTE DECK MECHANISM ...................................................................18
2. BLOCK DIAGRAM .......................................................................................................................................22
3. TERMINOLOGY REFERENCES.................................................................................................................23
4. SCHEMATIC DIAGRAM .........................................................................................................Separate Sheet
5. IC, TRANSISTOR LEAD IDENTIFICATION ................................................................................................25
6. UPPER CABINET EXPLODED VIEW (DECK UNIT 1) ...............................................................................26
LOWER CABINET EXPLODED VIEW (DECK UNIT 2)...............................................................................27
7. PARTS LIST FOR CABINET & CHASSIS ...................................................................................................28
8. PC BOARD ASS'Y (UPPER MAIN) PARTS LOCATION.............................................................................29
PC BOARD ASS'Y (LOWER MAIN) PARTS LOCATION............................................................................31
9. PC BOARD ASS'Y (UPPER MAIN) PARTS LIST .......................................................................................33
10. PC BOARD ASS'Y (HEAD 1, 2) PARTS LIST.............................................................................................41
11. PC BOARD ASS'Y (HEAD 1, 2) PARTS LOCATION ..................................................................................41
12. PC BOARD ASS'Y (SCART) PARTS LIST..................................................................................................42
13. PC BOARD ASS'Y (SCART) PARTS LOCATION.......................................................................................42
14. PC BOARD ASS'Y (LOWER MAIN) PARTS LIST.......................................................................................43
TABLE OF IC PIN VOLTAGE ......................................................................................................................52
MV-8080G_2 Con(1) 97.12.10, 20:40Page 1 Adobe PageMaker 6.0J/PPC

2
MAINTENANCE PRECAUTIONS
Since this model is a twin-deck system, some of the items to be adjusted during maintenance can be hard to
reach. (These parts are marked with an ¾in the table below.)
○:Serviceable item
#:Difficult
¾:Cannot be serviced
ELEC. ADJ. MECHA. ADJ. Treatment of the solder side
SWing Point e.t.c. DECK Adj. on the Main PCB
Upper 1○2○3¾
Lower 4○5¾6¾
External 7○or #8¾9○
Items 3, 5, 6, 7and 8in the table above cannot be serviced in their current positions. To service these
parts, move the parts marked ¾to those marked ○on the Deck Unit (a single deck VCR or VCP, including Deck
mechanism and Main PCB). in the table. After testing that the serviced items work, replace the Deck Unit in its
original position.
Maintenance
Position
of the Deck Unit
12 12
356 3
99
()
¾
Deck Unit 1
Deck Unit 2
Deck Unit 2
Deck Unit 1
AC IN
AC IN
AC IN
SYNCHROSCOPE
AC IN
Pattern (C) External Position (Upside Down) Pattern (D) External Position (Upside Down)
*Operation cannot be tested with the deck mechanism alone.Temporarily assemble the mechanism with the Main PCB
to test the mechanism.
To test Pattern (B), remove the Flexible Wire Harness, then exchange the Deck Mechanism Unit 2 with Deck
Mechanism Unit 1 and reconnect the parts.
To test Patterns (C) and (D), remove the Flexible Wire Harness, then the Deck Mechanism and Main PCB (in this
order) from the Chassis. Then temporarily assemble the removed Main PCB and Deck Mechanism and reconnect
the parts. To do this, fix the two spacers of the Deck Mechanism to the back of the Main PCB with screws.
External Position
Upper Position
Flexible Wire Harness
Lower Position
44
()
¾
Cannot be serviced.56
Deck Unit 2
Deck Unit 1
Deck Unit 1
Deck Unit 2
1
88
¾
#7
7
¾Cannot be
serviced.
Pattern (A) Original Position Pattern (B) Upper and Lower Deck Unit
Positions Inverted
MV-8080G_3(2~4) 97.12.10, 20:41Page 2 Adobe PageMaker 6.0J/PPC

3
Pattern (C) External Position (Upside Down)
Deck Unit 1
9Treatment of the solder side
on the Main PCB
*Fix the two spacers of the Deck Mechanism
to the back of the Main PCB with screws.
Deck Unit 2
R1713 1Switching
Point Adjust-
ment OK
Deck Unit 1
Deck Unit 2
2Mechanical Adjustment OK
Pattern (A) Original Position
MV-8080G_3(2~4) 97.12.10, 20:41Page 3 Adobe PageMaker 6.0J/PPC

4
2Mechanical Adjustment OK
Deck Unit 2
Deck Unit 1
Pattern (B) Deck Unit 1 and 2 Positions Inverted
Pattern (D) External Position (Upside Down)
*Fix the two spacers of the Deck Mechanism
to the back of the Main PCB with screws.
R1713 1Switching
Point Adjustment OK
9Treatment of the solder side
on the Main PCB
Deck Unit 2
Deck Unit 1
MV-8080G_3(2~4) 97.12.10, 20:41Page 4 Adobe PageMaker 6.0J/PPC

5
ELECTRICAL ADJUSTMENT
1. PLAYBACK SWITCHING POINT ADJUSTMENT
Mode : PLAY
Test Signal : TPS-13 or 13S
Check Point : FIP
Procedure
DECK TYPE
Adjustment
Point
1)
2)
3)
4)
R1713 CH UP/DOWN (55
55
5/∞∞
∞∞
∞) KEY
Plays the adjustment tape and automatically adjusts ATR. The ATR is finished when “ATR” on
the FIP stops blinking.
Short the connection between PG ADJ and GND on the MAIN PCB as indicated in Figure 1.
Then, must of the segments on the FIP, for example, “ATR” goes OFF. See Figure 2 below.
PG ADJ (J257), GND (J259) PG ADJ (J228), GND (J230)
Clear the TEST POINT short.
To adjust the display for FIP (H701), (Display
B below).
• Press the Down ∞key (in case of Display A)
• Press the Up 5key (in case of Display C)
FOR UPPER DECK UNIT 1 WITH POWER
SECTION FOR LOWER DECK UNIT 2 WITH TUNER
To adjust the display for FIP (H1071) (Display
B below.)
• Turn R1713 to the right (in case of Display A)
• Turn R1713 to the left (in case of Display C)
AMP
CTL
RFS
GND
PG ADJ
J282
J258
J260
J259
J257
R1713
PG ADJ
Figure 1-1
MAIN PCB WITH POWER SECTION FOR
UPPER DECK
Figure 1-2
ADJ
GND
PG ADJ
J229
J230
J228
MAIN PCB WITH TUNER FOR LOWER
DECK
Display A Display B Display C
Adjustment
completed.
: ON
Figure 2
Due to major changes in the electrical circuits, it is sufficient to perform only this section, “PLAYBACK
SWITCHING POINT ADJUSTMENT,” of the electrical adjustments.
MV-8080G_4(5 97.12.11, 9:45Page 5 Adobe PageMaker 6.0J/PPC

6
MECHANICAL ADJUSTMENT
DECK ADJUSTMENT POINTS
1FM Waveform (Envelope) entrance adjustment screw
2FM Waveform (Envelope) exit adjustment screw
3Audio Azimuth adjustment screw
4Control Head phase (X-value) adjustment point
5Audio/CTL Head height adjustment screw
6A/C Head tilt adjustment screw
7RG Post height adjustment screw
1254367
MV-8080G_5(6~16) 97.12.11, 9:36Page 6 Adobe PageMaker 6.0J/PPC

7
POSITION NAME
POSITION NO E
J
E
C
T
S

R
E
W

E
SL O
A
D

R
E
W
F
FS T
O
P
P
L
A
Y
C
T
R
E
V
E
R
S
E

F

S
L
O
W
R

S
L
O
W
SWITCH
ON/OFF
TIMING
POSITION
CODE
WHITE=OFF
BLACK=ON
1=OFF
0=ON
M1 SW
M2 SW
M3 SW
M4 SW

COM SW
COM-M1
COM-M2
COM-M3
COM-M4
0 1 0 1 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 0 1 0 1
0 1 0 1 1 1 1 1 1 0 1 0 1 1 1 1 1 0 1 1 1 0 1
1 1 1 1 1 1 1 1 1 1 1 0 1 0 1 0 1 1 1 0 1 0 1
1 1 0 1 0 1 1 0 1 0 1 0 1 0 1 1 1 1 1 1 1 1 1
MODE SW
Equivalent 
Circuit
COM
COM
SW
M1
M1
SW
M2
M2
SW
M3
M3
SW
M4
M4
SW
1 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23234
1. MECHANISM CONTROL
The mechanism includes its own mode as well as the operation mode of the VCR as shown in the chart below. This mode serves
an important function in working to protect the tape by passing through the VCR when the mode is switched over.
The movement of the mechanism mode is performed by the control signal of the loading motor’s rotary control circuit. With this
control, the operation mode position is detected by the Mode switch (4-bit mode data output), Cassetle ln switch, tape top sensor
and the tape end semsor which detects all modes of the mechanism.
1-1. MODE SW
The composition of the 4 terminals, COM DATA 1, 2, 3, 4, are treated as a 4 bit signal.
1-2. CONFIGURATION OF THE
TN6500 VCR MECHANISM
1-2-1. Cassette Drive Mechanism
The cassette is loaded and ejected via the drive from the
capstan motor.
(A) Detection of cassette insertion
When an cassette is inserted, the capstan motor starts and
simultaneouslycausestheshutteronthemainunit to break thelight
beamoftheTapeTopSensor.ThiscapstanFGpulseandtheTape
Top Sensor change cause the cassette to be pulled into the VCR.
(B) Detection of completed cassette insertion operation
Thisisdetected bytheCassetteInsertion Switchthatis linked to
the actuator activated when a cassette is inserted.
Note: The Cassette Insertion Switch is not included
with the deck mechanism.
(C) Detection of completed cassette ejection operation
As above, this is detected by the shutter on the shutter
detecting the change in the Tape Top Sensor. The light
beamthatisbrokenbycassetteinsertion/ejectionisrestored
when the cassette has been ejected.
1-2-2. Tape Loading Mechanism
Tape loading mechanism is the mechanism that is loaded
with the tape loading motor linked to the mode switch. The
following actions occur when the 4-bit position code output
from the mode detection switch is used.
(A) The tape is pulled out of the cassette and wound on the
cylinder. (tape loading)
(B) The tape is returned to the cassette. (tape unloading)
(C) Function are switched so that each mechanism can operate.
1-2-3. Tape Transportation Mechanism
The tape is fed through the VCR by the action of the capstan,
pinch roller and reel drive.
1-2-4. Motor
(A) Capstan Motor
The drives the capstan axle directly and also drives the reel
that has been loaded on the belt. This motor is also used to
drive the cassette loading mechanism.
(B) Tape Loading Motor
In addition to cassette loading/unloading, this motor also
switched between the various operating modes(PLAY, FF/
REW etc. )
(C) Cylinder Motor
Connected to the rotating head drum and drives the rotating
head.
1-2-5. Safety Tab Sensor/Actuator
This actuator detects the tab that operates the REC SAFETY
switch.
Note: This mechanism does not include the switch.
1-2-6. Mode Sensor Switch
Thisdetectsthe 4-bit codebeforeeachposition and isconnected
to the tape loading mechanism.
1-2-7. Take-up/Supply Reel Sensor
Photoelectric Cell
A luminous diode and phototransister at the fixed position for the cell
comprise the reel sensor. (Pulse rate=8pulses/rotation)
Note: This mechanism does not include the luminous diode
or the phototransister.
1-2-8. Tape Start/End Sensor Photoelectric Cell
A luminous diode and phototransister at the fixed position for the cell
comprise the start/end sensor. (Pulse rate=8pulses/rotation)
Note: This mechanism does not include the luminous diode
or the phototransister.
MV-8080G_5(6~16) 97.12.11, 9:36Page 7 Adobe PageMaker 6.0J/PPC

8
2. ADJUSTMENT OF BTTORQUE IN PLAY MODE
(ADJUSTMENT OFTHE TENSION ARM POSITON)
1. Remove the FL Ass’y.
2. Rotate the loading pulley with your finger until PLAY mode is reached.
3. Insert a standard screwdriver into the BT adjustment groove (a or b) of the main chassis.
Twist the screwdriver left and right to adjust gap (A) and gap (B) so that they are the same.
CAUTION: Do not twist at too much of an angle. Doing so will have adverse effects on other areas as well.
• To reduce the gap (BT torque reduction), insert into
adjustment groove “a” and twist counter-clockwise as
shown in the figure below.
• To increase the gap (BT torque increase), insert into
adjustment groove “b” and twist clockwise as shown
in the figure below.
a b
eVA[
BTohAZu
[AZ
u
BT†fipa
[fBOubN
[a
B
AA=B
Loading Block Rail Groove
Tension Arm
BT Band Ass'y
Reel Ass'y
BT adj. Groove
MV-8080G_5(6~16) 97.12.11, 9:36Page 8 Adobe PageMaker 6.0J/PPC

9
3. AUDIO/CTL HEAD
3-1. TAPETRANSPORT ADJUSTMENT
Audio/CTL Head Adjustment
1. Using an ordinary cassette tape, set to CUE mode.
2. Turn screw Cand adjust for smooth transport at the
take-up guide.
3-2. AUDIO/CTL HEAD HEIGHT AND
AZIMUTH ADJUSTMENT
1. Connect the noise meter to the audio output.
2. Play the test tape (1 KHz color bar signal), turn screw
Aback and forth a little at a time to set maximum
audio output level. (Rotate in a clockwise direction to
adjust the settings.)
3. Play the test tape, (8 KHz stair step signal), turn
screw Bback and forth a little at a time to adjust the
azimuth so that the audio output level will reach a
maximum.
4. Play the test tape (1 KHz color bar signal), and make
sure that there is no significant change in the audio
output level. If a large change remains, turn screw C
back and forth a little at a time to adjust so that the
level change will reach a minimum.
5. When all adjustment is finished, lock up screw B.
4. TAPETRANSPORT SYSTEM
CHECKS AND ADJUSTMENT
The tape transport system has been precisely
aligned at the factory and normally does not
require readjustment. The following steps are
therefore necessary only in cases of frequent use
or when replacing parts which have an effect on
the tape transport system.
4-1. TAPETRANSPORT CHECK
1. Using an ordinary cassette tape, switch back and
forthbetweenPLAYandSTOPmodesseveral times.
2. During PLAY mode, observe the input and output
portions of the tape (A and B in the figure below) of
the head drum lead. Confirm that the tape slips
neither upward nor downward with respect to the
lead as shown in Figure “Drum Lead Check-1”.
Tape Transport Check
Drum Lead Check-1
“«ŁKCh
e[v
e[
v
A DB EC
ªhAZu
h[hi”ßj e[v
Tape
Tape
Take-up Guide
A:hß B:ho
Upper Drum Ass'y
Drum Lead (lower) Tape
Drum OutputDrum Input
Tape
Take-up Guide Pole
Audio Head
CTL Head
Reference line
Approx.
0.06mm
MV-8080G_5(6~16) 97.12.11, 9:36Page 9 Adobe PageMaker 6.0J/PPC

10
4-2. GUIDE ROLLER HEIGHT
ADJUSTMENT
1. Slightly loosen the tight-screw of the supply and take-
up guide rollers as shown in the figure below.
2. Using an ordinary cassette tape, set to PLAY mode.
3. With a standard screwdriver, slightly turn the supply
guide roller (no more than 180° at a time), and adjust
so that at the drum input portion, the tape travels
smoothly along the drum lead without slipping
upwards or downwards.
4. Similarly, adjust thetake-uprollerfor the drum output.
Adjusting Guide Roller Height
NOTES:
1. Loosen the tight-screw only enough to allow
the guide rollers to be rotated. Loosening it
anymore than that may rotate the roller
inadvertently as a result of tape motion.
2. Rotate the roller carefully to avoid damage to
the tape.
3. When the adjustment is completed, tighten the
screw and set by locking up the screw.
Correct
Guide
roller
Tape
Incorrect
AB C
NOTES:
1. If the tape slips upward; sound is produced by
contact between the tip of rotating heads and
the edge of the tape.
2. If the tape slips downward; the tape curls or
wrinkles (or makes noise) at its connection
with the lead face of the drum lead.
3. During loading, play, and unloading of the
cassette tape, observe the tape at the supply
guide roller, and take-up guide roller.
4. Make sure that there arenocurlsorwrinklesas
shown in the figure below.
Guide Roller
5. Observe the tape as it wraps around the drum
during PLAY and separates from the drum
during STOP.
6. As shown in the figure below, make sure that
there is no damage to C and D and that there
is no contact noise between the head tips and
tape edge.
Drum Lead Check-2
7. If a defect is detected during check, perform
the follwoing procedure for adjusting Guide
Roller height.
C
D
Ło
KCh[
e[v ªhAZu
“«Ł
KCh[
h[h
Tape Upper Drum Ass'y
Drum Lead
Supply Guide Roller Take-up
Guide Roller
KCh[
¯ŁlW
hCo[¯æ
Turn with a
standard screwdriver
Guide Roller
Tight Screw
MV-8080G_5(6~16) 97.12.11, 9:36Page 10 Adobe PageMaker 6.0J/PPC

11
4-3. TAPETRANSPORT CHECK AT
THETAKE-UP GUIDE
In general, no adjustment will be necessary for the take-
up guide. However, adjustments or checks will be
necessary when replacing the Audio/CTL Head or parts
affecting the tape transport system after a long period of
operation.
1. Using an ordinary cassette tape, set to PLAY mode.
2. Turn Audio/CTL Head screw Cas shown in the
figure below and adjust for smooth transport at the
Take-up Guide.
5. INTERCHANGEABILITY
ADJUSTMENT
Before using the test tape, make sure that the tape
transport is normal using an ordinary cassette tape.
Also, make sure that the switching point (Refer to P.5)
is adjusted. If they are not, do the following checks after
adjusting.
5-1. PRELIMINARY CHECKS
1. FM Envelope Waveform Check
1. Connect the CH-1 oscilloscope to TP of PB ENV and
CH-2 to TP of CTL. At this time, trigger the
oscilloscope externally with the signal (RF Switching
Pulse) from TP of RFS.
2. Play the test tape (Stairstep).
3. Use the Channel ∞/5buttons to tune the tracking to
center position. Adjust point 4(X value adjustment
point: test point reference P.6) so that the FM
envelopeoutputatTPofPBENVreachesamaximum.
“«ŁKCh
e[v
e[
v
A DB EC
Tape
Tape
Take-up Guide
4. UsingtheChannel∞/5buttons.Performthefollowing
3 steps (5-7) by moving the TP of CTL waveform in
both positive (+) and negative (–) directions in 3 ms
increments.
5. Refer to the figure below. Read the level of portion
(a) of the waveform. If the waveform is serrated at
point (a), adjust the level so that the serrations are as
smooth as possible (refer to the second figure).
FM Waveform (Maximum Output)
Normal Waveform Examples
Ideal FM envelope
a
abd
ce
Minimum levelMaximum level
X|WVAWXg¡
X position Adjusting Jig
MV-8080G_5(6~16) 97.12.11, 9:36Page 11 Adobe PageMaker 6.0J/PPC

12
5-2. ADJUSTMENT
1. Connect the TP of PB ENV to the oscilloscope
CH-1. At this time, trigger the oscilloscope externally
with the signal (RF Switching Pulse) from TP of RFS.
2. Play the test tape (Stairstep).
1. DRUM INPUT ADJUSTMENT
1. Observe the FM envelope output wave at the TP of
PB ENV with the oscilloscope and press the
CHANNEL ∞/5buttons in both positive (+) and
negative (–) directions.
2. A of the following figure shows incorrect waveforms.
With a standard screwdriver, adjust the transport
guide roller to flatten the peak of the FM envelope
waveform as shown in B.
NOTES:
1. If the guide roller rotates freely, tighten the
screw slightly.
2. Be sure to adjust the guide roller only by small
increments at a time to avoid damaging the
test tape.
In addition to observing the waveform, make
sure that there is no slipping of the tape or
curling at the drum lead.
=
c
ad
a=
c
a
e
a
> 0.75 and > 0.75 or
20 log = –2.5 dB and
20 log = –2.5 dB
> 0.75 or 20 log > –2.5 dB
==
b
a
b
a
6. As shown in the equation below, read the FM
waveform value at point (b) and make sure that:
7. Read the values at points (c) and (d) [drum input and
output] and make sure that:
NOTES:
1. Read the minimum levels for (b), (c), and (d).
2. If above checks yield normal results, proceed
to page MA-8 section “ADJUSTMENT”.
3. If defects are noted, perform the following FM
envelope waveform adjustment.
2. FM ENVELOPE WAVEFORM
ADJUSTMENT
1. As in the previous section, observe the FM waveform
and press the CHANNEL ∞/5buttons. Waveform
alterations must be nearly parallel to each other as
shown in Figure “Normal Waveform Examples” on
page P.11.
2. If the waveform changes as shown in the figure
below, adjustment is necessary.
Abnormal Waveform Example
Drum Input Adjustment
Drum input
AB
Supply Guide RollerTape
Tight Screw Supply Guide Roller
MV-8080G_5(6~16) 97.12.11, 9:36Page 12 Adobe PageMaker 6.0J/PPC

13
2. If there are waveforms as shown in A or B in the
above figure, adjust the supply guide roller height so
that the waveform appears as shown by E, F, or G
in the figure below. At this time, if the waveform
fluctuates, adjust to the point of minimum fluctuation.
Minimum FM Output (Correct Examples)
E
F
G
Taper
Parallel
Taper
Maximum
AC
DB
NOTES:
1. Fine adjustments are not required at this time.
It is sufficient if the tape is engaged with the
guide and that the servo operates properly
(control signal picked up).
2. If the tape separates from the take-up guide or
wrinkling occurs, screw Cmust have been
excessively tightened with respect to screw A
and screw B, which is causing the Audio/CTL
Head to incline forward or backward. Use care
in adjusting screws Band C, and screw A
evenly and observe that wrinkles are not
produced at the take-up guide.
5-3. INTERCHANGEABILITY
ADJUSTMENT
1. Observe the FM envelope output waveform at the
oscilloscope and press to adjust the CHANNEL ∞/5
buttons in both positive(+) and negative(-) directions.
Minimum FM Output (Incorrect Examples)
3. As shown in the figure below, adjust screws Band
Cand screw Ato align the Audio/CTL Head
height with the tape.
Audio/CTL Head Height
Drum output
CD
2. DRUM OUTPUT ADJUSTMENT
1. Adjust the take-up guide roller so that the FM
envelope output flattens as shown in D of the figure
below.
Drum Output Adjustment
2. If the tape separates from the guide or wrinkling
occurs at the take-up guide, adjust by turning screw
Cof the Audio/CTL Head as shown in the figure
below.
Take-up Guide
“«Ł
KCh[
¯ŁlW
AB E
“«Łe[vKCh
e[v
e[v
DC
Tape
Take-up
Guide Roller
Tape
Take-up Guide
Tight Screw
Approx.
0.06mm
Take-up Guide Pole
Reference line
Tape
CTL Head
Audio Head
MV-8080G_5(6~16) 97.12.11, 9:36Page 13 Adobe PageMaker 6.0J/PPC

14
3. If the FM waveform appears as shown by C or D in
the above figure, adjust the take-up guide roller
height to obtain a waveform such as shown in E, F,
or G.
At this time, if the waveform fluctuates, adjust to the
point of minimum fluctuation.
4. Vary the tracking control from maximum to minimum
FM output.
Perform fine adjustment of supply and take-up guide
rollers so that waveform variation appears as shown
in E, F, or G.
5-4. AUDIO/CTL HEAD HEIGHT,
AZIMUTH AND SLANT
Refer to 3-2 (P.9) for details regarding AUDIO/CTL
HEAD HEIGHT AND AZIMUTH ADJUSTMENT.
5-5. SETSCREWTIGHTENING
1. Check for maximum FM output waveform, maximum
audiooutput,andbesurethatthereisnowrinklingon
the tape or other transport irregularities. When
finished, secure the guide rollers. (This must be
performed in STOP mode.)
2. Because the guide rollers are easily moved, use care
when securing.
3. After tightening the screws, perform the final inter-
changeability check.
5-6. FINAL INTERCHANGEABILITY
CHECK
Perform preliminary checks referring to section “PRE-
LIMINARY CHECKS” on page P.11.
E
1) Use a blank tape and set the VCR to REV mode.
2) Adjust the RG Post height adjusting screwEso that
the tape runs along the lower flange of the Take-Up
Guide.
Tape
6. RG POST HEIGHT ADJUSTMENT
RG Post
Take-Up Guide
MV-8080G_5(6~16) 97.12.11, 9:36Page 14 Adobe PageMaker 6.0J/PPC

15
7. FRONT LOADING ASSEMBLY ATTACHMENT
To attach the Front Loading Assembly, follow the procedures below.
1) Twist the loading motor with your finger until it is in
EJECT mode.
2) Twist the FD Pinion Gear counterclockwise until it
stops. (The FD Face Gear is loose. )
3) Twist the FD face Gear counterclockwise until it
stops, then apply gentle pressure in the
counterclockwise direction.
4) In the position at step 2) , rotate the FD Pinion Gear
clockwise.Afterabout31/2turns,theFDPinionGear
should begin to interlock with the FD Relay Gear.
Now twist the FD Pinion Gear until it stops. (The
assembly should now resemble Fig. 2)
5) Twist the FD Pinion Gear about 1/3 of a turn
counterclockwise so that the Lift Gear R attachment
position is horizontal making attachment easier, as
shown in Fig. 3. Also, the FD Relay Gear and FD
Face Gear eye marks should be aligned when the
MD is viewed from the back. (Fig. 4)
6) Attach the front assembly.
Insert the first Lift Gear R between the first and
second gear of the front assembly. (Fig. 3)
Note: DonottouchtheCSPplateoftheFrontLoading
Assembly. (Take care not to distort it.)
4
2
3
Fig. 1 View from above the MD Fig. 2 Fig. 3
Lift Gear R
FD Gear Case
FD Face Gear
FD Pinion Gear
FD Gear Case
FD Relay Gear Align first gear on Lift Gear R.
Eye mark
Fig.4 MD Rear View
CSP plate
Front Loading A'ssy
MV-8080G_5(6~16) 97.12.11, 9:36Page 15 Adobe PageMaker 6.0J/PPC

16
PERIODIC MAINTENANCE
The following procedures are recommended for main-
taining optimum performance and reliability of this video
cassette recorder.
CLEANING
For cleaning, use a lint-free cloth or gauze dampened
with alcohol.
TAPE TRANSPORT SYSTEM
1. The following components should be cleaned after
every 500 hours of use.
• Impedance Roller
• Tension Post
• Transport Slide Post
• Supply Guide Roller
• Take-up Slide Post
• Take-up Guide Roller
• Video Head & Drum System
• Drum Ground
• Drum Motor Shaft
• Audio/CTL Head
• Pinch Roller
• Capstan
• Reverse Guide Post
• Full Erase Head
• Tape Guide
• F Post
2. Since the above parts come in direct contact with
video tape, they tend to collect dust particles. If
allowed to accumulate, dust may lead to damage to
the video tape and above parts.
3. After cleaning with alcohol, allow the parts to dry
thoroughly before using a cassette tape.
NOTE:
• When cleaning the two video heads on the
upper drum, do not clean them with a vertical
stroke.
• Use only a gentle back and forth motion in the
direction of the tape path.
REEL DRIVE SYSTEM
1. The following components should be cleaned after
every 1000 hours of use.
TOP BOTTOM
• Take-up Reel Table Ass’y • Capstan Motor Pulley
• Supply Reel Table Ass’y • Clutch Pulley
• T Soft Brake Ass'y • Drive Belt
• T Main Brake Ass'y • C Brake
• S Main Brake Ass'y
• BT Band Ass'y
2. The above revolving parts are of rubber or come in
direct contact with rubber parts. Dust on rubber
accumulates and interferes with proper operation.
3. Avoid using excessive alcohol when cleaning rubber
parts.
MV-8080G_5(6~16) 97.12.11, 9:36Page 16 Adobe PageMaker 6.0J/PPC

17
Description
SERVICE SCHEDULE FOR MAIN COMPONENTS
The following table lists the parts which should receive periodic servicing at the recommended intervals.
Periodic Service Schedule (operating hours)
Ref. No Part No. 1000 2000 3000 4000 5000
1 62D806501603 Cylinder Ass’y for 59277 ●●
1 62D806501603 Cylinder Ass’y for 59311 ●●
90 62D806506301 Pinch Roller Arm Ass'y ●●
116 62D806508303 BT Band Ass’y ●●
128 62D806509302 Clutch Ass’y ●●
131 62D80650920 Drive Belt ●●
132 62D806510301 T Main Brake Ass’y ●●
133 62D806510302 S Main Brake Ass’y ●●
134 62D806510303 T Soft Brake Ass'y ●●
61 62D62041520 A/C & E Head for 59277 ●
61 62D62040324 Audio/CTL Head for 59311 ●
80 62D806505301 T Reel Ass’y
81 62D806505302 S Reel Ass’y
100 62D60030360 Capstan Motor Ass’y
142 62D806511303 Loading Motor Ass'y
Standard Service Periods Check and replace if necessary
●Replace
NOTE:
Cleaning and replacement of the belts should be undertaken every 2 years even if the unit is not used frequently.
MV-8080G_6(17~18) 97.12.11, 9:49Page 17 Adobe PageMaker 6.0J/PPC