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Notes:
• Before the adjustment:

Electrical adjustments discussed here are often required after replacement of electronic components and mechani-
cal parts such as video heads.
Check that the mechanism and all electric components are in good working condition prior to the adjustments,
otherwise adjustments can not be completed.

• Instruments required:

Colour TV monitor
Dual-trace oscilloscope

         Alignment tape (VROCPSV)

Blank video cassette tape
DC voltmeter
Screwdriver for adjustment

Servicing precations
When the IC705 (E

2

PROM) has been replaced, make the following reprogramming. Depending on models, the IC705

(E

2

PROM) has been factry-adjusted for it’s memory function.

It’s therefore necessary to reprogram the memory function for the model in question.
Note that the servo circuit requires readjustments for the head switching point, slow and still modes.

P201

P1501

P802 P801

R1626
RF AGC

IC1602

TU1551

SC1501

T1601
VCO

SW813 SW806 SW811

SW810 SW807

SW812 SW808 SW809

Measuring
instrument

Mode

Cassette

Dual-trace oscilloscope
Colour TV monitor

Playback

Alignment tape (VROCPSV)

Test point

Pin(2) of P201 (H.SW.P.) to CH-1,
VIDEO OUT jack to CH-2
(CH-1 trigger slope switch at (+),
Internal trigger at CH-1 side.)

Specification

6.5 

±

 0.5H (lines)

1. Remove the front panel and play the alignment tape.

(VROCPSV)
(Playback picture on the monitor screen.)

2. Press the PLAY button.
3. Make for a moment short-circuit P802, located at the

front side on the main PWB.
Be sure that all the fluorescent display tubes light up
into the TEST mode.(See Note below)
Be sure the "PLAY" appears in the fluorescent display
tubes flashing (about 1Hz) into the auto PG adjust-
ment operating.

When the manual PG adjustment, obseve the wave-
form with an oscilloscope and make adjustment FF or
REW button so that the specification.

4. Stop the "PLAY" appears in the flashing of fluorescent

display tubes at adjusted.

5. Press the STOP button in the return to normal mode.
6. Make this checking of waveform on the oscilloscope

screen be as shown in Figure 5-2. just after the head
switching point have been adjusted.

1

Set-up of TEST mode.
When the adjustment of HEAD SWITCHING POINT,
AUTO TRACKING function is invalid.

2

When the cassette housing control ass’y is removed,
set-up of mechanism operating mode.

1) Replug the AC power cord it a few minutes later.
2) Make a short-circuit P801 located at the front side on

the main PWB, and press both tracking control button
at the same time to set the tracking in center.

3) AC power cord is plugged in.
4) You can mechanism operatig mode, Replug the AC

power cord a few minutes later.

Measuring
instrument

Mode

Cassette

Colour TV monitor

Playback

Self-recorded tape
(SP/LP mode)(See Note below)

Control

Tracking control buttons (+) or (–)

Specification

Minimized noise on
monitor screen

6.5

±

0.5H (lines)

CH-1: 1V/div 50

µ

s/div

CH-2: 2V/div 50

µ

s/div

V-sync.

CH-1
HEAD
SWITCHING
PULSE

CH-2
VIDEO OUT

1. Have the unit to receive a good TV broadcast or feed

a video signal to the VIDEO IN jack. (See note 

2

below)

2. Set the tape speed in SP mode by using the remote

control and record the signal on tape.

3. Rewind and play the tape where signal was recorded

in above step.

4. Press the SLOW button on the remote control, and

playback the recorded portion in the slow mode.

5. Make for a moment short-ciucuit  P802, located at the

front side on the main PWB.
Be sure that all the fluorescent display tubes light up
into the TEST mode.

6. Look at the monitor screen and adjust the (+) or (–)

TRACKING buttons so that the there is noise disap-
pears from the screen.

7. Press the STOP button to return to normal mode.
8. Play the tape a few seconds then press the SLOW

button again and make sure there is on noise in the
screen.(For the LP mode put adjustment at the same
adjustmet way as SP mode.)

1

Self-recorded tape means a cassette whose pro-
gram was recorded by the unit being adjusted.

2

The TV program will not be recorded if RCA or 21pin
plugs are pluged in to the AUDIO/VIDEO input
terminals.

Measuring
instrument

Mode

Test point

Colour TV monitor
DV voltmeter

RF signal at 40CH(by VHF
signal generator)

Pin(2)(Sig.) of P1501.
Pin(4)(GND.) of P1501.

Control

R1626 RF AGC control

Specification

4.3

±

0.2V(G/S Hi-Fi models)

1.Receive the 40 channel signal(colour bar signal at
   87.5% modulated.) at input field strength: 57dB

µ

 of

   antenna terminal.
2.Connect a DC voltmeter to test point shown in table.
3.Look the voltmerter and adjust R1626 so that the
   voltage be specified.

Measuring
instrument

Mode

Test point

Colour TV monitor
DV voltmeter

Control

T1601 VCO control

Specification

2.5

±

0.2V

RF signal at 40CH(by VHF
signal generator)

Pin(1)(Sig.) of P1501.
Pin(4)(GND.) of P1501.

When power is turned on, tune in to station in the test
mode.

1.Receive the 40 channel signal(colour bar signal at
   87.5% modulated.) at input field strength: 70dB

µ

 of

   antenna terminal.
2.Connect a DC voltmeter to test point shown in table.
3.Look the voltmerter and adjust T1601 so that the
   voltage be specified.

Measuring
instrument

Mode

Cassette

Colour TV monitor

Playback still

Self-recorded tape (SP mode)
(See Note below 

2

)

Control

Tracking control buttons (+) or (–)

Specification

No vertical jitter of picture

1. Play a cassette which was recorded by the unit in SP

mode.

2. Press the PAUSE/STILL button to freeze the picture.
3. Look at the monitor screen and adjust (+) or (–)

TRACKING buttons so that the vertical jitter of the
picture to be minimized.

4. Play and freeze the self-recorded tape in SP mode

and make sure vertical jitter of the picture is not
noticeable.(For the LP mode put adjustment at the
same adjustment way as SP mode.)

1

The FV goes back to the it’s initial state when the unit
is put into the system controller reset mode due to
power failure, etc.
In this case, preset the FV once again.

2

Self-recorded tape is a cassette whose program was
recorded by the unit being adjusted.

;;

;;

;;;

0

5

10

15

20

25

F mechanical timing

Mode

Rotation angle

Mode check

Cam mark

Mode detection outside

(D705  SW  B)

Mode detection inside

(D708  SW  A)

Cam graph  E

60

120

180

240

300

360

CA/END

CS/EJ

      33.82

UL

81

VSR

218

PU(LD)

188

PB

252

SLOW

269

CL

293

STOP

309

FF

325

Cam switch

0

Mode detection outside

Mode detection inside

S sensor

S sensor

Mode detection inside

Sensor A

Mode detection outside

Sensor B

CS/EJ

ULD

PU  LD

VSR

PB

STILL

CL

STOP

FF

1

1

1

0

0

0

0

0

0

0

1

1

1

0

1

0

0

0

open

close

0

1

EJ

UL

FF

PU

0

1

1

0

0

0

0

1

1  or  0

1

1

1

0

10

0

0

0

0

1

1

1

1

1

1

VSR

PB

SLW

S

TP

CL

0

;

;

Loading motor turns in reverse

direction and master cam

counterclockwise.

Cassette

inserting

Full-

loading

Unloading

Loading motor starts in normal

direction and master cam counter

clockwise.

Does mechanism position sw.

come off within 2.5 sec.?

Are start/end sensors at low level

before cassette insertion ?

Insert cassette.

Double action rack slides.

Drum motor starts.

Tape loading.

Pinch roller comes into contact.

Cam switch is at PB position.

Loading motor stop.

Is drum FG pulse outputted ?

End

End

Cassette is ejected and loading

motor stops.

Start sensor close.

(Cassette is judged

caught halfway.)

(Cassette LED or some other part

is judged defective.)