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5

This unit is equipped with a self-diagnosis function.
The function is used for diagnosing the conditions of the circuits of
the VIDEO board.
The circuits can be determined if normal or abnormal by the light-
ing of D502 of the VIDEO board.

Lighting of D502
When lit

: Operates normally

Blinks repeatedly : The circuit may be faulty.

The laser diode in the optical pick-up block may suffer electrostatic
break-down because of the potential difference generated by the
charged electrostatic load, etc. on clothing and the human body.
During repair, pay attention to electrostatic break-down and also
use the procedure in the printed matter which is included in the
repair parts.
The flexible board is easily damaged and should be handled with
care.

The laser beam on this model is concentrated so as to be focused on
the disc reflective surface by the objective lens in the optical pick-
up block. Therefore, when checking the laser diode emission, ob-
serve from more than 30 cm away from the objective lens.

CN501

1

30

80

SL501

SL502

SL503

CN502

51

IC505

31

50

100

81

D502

6

• The cold reset clears all data including preset data stored in the RAM to initial conditions. Execute this mode when returning the set to the

customer.

Procedure:
1. Press three buttons  

p  ,  ENTER/NEXT  , and  1/u  simultaneously.

2. “COLD RESET” is displayed on the fluorescent display tube and reset is executed.

• This mode moves the optical pick-up to the position durable to vibration. Use this mode when returning the set to the customer after repair.
Procedure:
1. Press  

1/u  button to turn the set ON.

2. Press  CD LOOP  button and  

1/u  button simultaneously.

3. A message “LOCK” is displayed on the fluorescent indicator tube, and the CD delivery mode is set.

• This mode resets the set with the preset data kept stored in the memory.  The hot reset mode functions same as if the power cord is plugged

in and out.

Procedure:
1. Press three buttons  

p  ,  ENTER/NEXT  , and  DISC 1  simultaneously.

2. The fluorescent indicator tube becomes blank instantaneously, and the set is reset.

• This mode can run the CD sled motor freely. Use this mode, for instance, when cleaning the optical pick-up.
Procedure:
1. Press  

1/u  button to turn the set ON.

2. Press three buttons  

p  ,  ENTER/NEXT  , and  §  simultaneously.

3. The Sled Servo mode is selected, if “CD” is blanking on the fluorescent indicator tube.
4. With the CD in stop status, When the  

) +  button is pressed, the optical pick-up moves outside. When  – 0  button is pressed, it

moves inside.

5. To exit from this mode, perform as follows:

1) Move the optical pick-up to the most inside track.
2) Execute MC cold reset. (Press the three buttons  

p  ,  ENTER/NEXT  , and  1/u  button simultaneously.)

Note:
• Always move the optical pick-up to most inside track when exiting from this mode.  Otherwise, a disc will not be unloaded.
• Do not run the sled motor excessively, otherwise the gear can be chipped.

• A step of AM channels can be changed over between 9kHz and 10kHz.
Procedure:
1. Press  

1/u  button to turn the set ON.

2. Select the function “TUNER”, and press  TUNER/BAND  button to select the BAND “AM”.
3. Press  

1/u  button to turn the set OFF.

4. Press  ENTER/NEXT  and  

1/u  buttons simultaneously, and the display of  fluorescent indicator tube changes to “AM 9k STEP” or “AM

10k STEP”, and thus the channel step is changed over.

Procedure:
1. Press three buttons  

p  ,  ENTER/NEXT  , and  DISC 2  simultaneously.

2. LEDs and fluorescent indicator tube are all turned on.

Press  DISC 2  button, and the key check mode is activated.

3. In the key check mode, the fluorescent indicator tube displays “K 0 V0 J0”.  Each time a button is pressed, “K”value increases. However,

once a button is pressed, it is no longer taken into account.
“J” Value increases like 1, 2, 3 ... if rotating  

0 AMS )  knob in “+”  direction, or it decreases like 0, 9, 8 ... if rotating in “-” direction.

“V” Value increases like 1, 2, 3 ... if rotating  VOLUME  knob in “+”  direction, or it decreases like 0, 9, 8 ... if rotating in “-” direction.

4. To exit from this mode, press three buttons in the same manner as step 1, or disconnect the power cord.

7

• This mode is used for checking the AMS operations of the tape deck.

JIG
7-819-039-12 Alignment tape, AMS-110A

Procedure:
1. Press the  

1/u  button to turn the unit ON.

2. Set the tape (AMS-110A).
3. Press the three buttons  

p  ,  ENTER/NEXT  , and  DISC 3  button simultaneously.

4. “TEST MODE” is displayed on the fluorescent display tube.
5. Press the  FUNCTION  button and switch the function to the deck with the tape (AMS-110A).
6. Press the  CD SYNC  button. “AMS CHECK” is displayed on the fluorescent display tube and the tape is rewound.
7. AMS starts in the normal direction. If the AMS count is 2 at shut down, proceed to step 8.

“NG” is displayed at other times, and the deck stops.

8. AMS starts in the opposite direction. If the AMS count is 2 at shut down again, “OK” is displayed.

“NG” is displayed at other times.

Note: The  

p  button of CD section will become effective and the aging of CD section will stop sometime, if the buttons described in step 3

are not pressed simultaneously. In that case, press  

^  button and operate the CD section.

This model has the self-diagnosis function for the VIDEO and AUDIO decoder sections.
Immediately after the power on, the self-diagnosis function searches each operation of IC’s around the mechanism control microcomputer
(IC701).
The results can be checked by D502 of the VIDEO board.

Oscilloscope (Waveform)

Symptom

No error

MPEG decoder (IC506)
error

MPEG decoder (IC506)
or
DRAM (IC507) error

H

L

Light

2 time blinking

H

L

H

L

3 time blinking

CN501

1

30

80

D502

SL501

SL502

SL503

CN502

51

IC505

31

(GND)

CT503

VIDEO

Frequency

Adjustment

Check point

(27 MHz)

50

100

81

8

Aging Mode
This mode can be used for operation check of tape deck section.
• If an error occurred:

The aging operation stops and display then status.

• If no error occurs:

The aging operation continues repeatedly.

Procedure:
1. Load the tapes into the decks A and B respectively.
2. Press the FUNCTION button to select the function “CD”.
3. Press the PLAY MODE button to set the “ALL DISCS” mode,

and press the REPEAT button to “REPEAT” off.

4. Press three buttons of  

p , ENTER/NEXT , and DISC SKIP/

EX-CHANGE simultaneously.

5. The aging mode is activated, if the indicator of disc tray number

on the fluorescent indicator tube is blinking.

6. To exit from the aging mode, press the  

1/u  button to turn the

power OFF and operate the cold reset. (Refer to the “MC Cold
Reset”)

• The sequence during the aging mode is following as below.
• If an error occurred, stop display that step.

Rewind the tape A and B

“TAPE A AG-1”

Shut off

2 mimutes

Shut off or 20 seconds

2 minutes

2 minutes

Shut off or 20 seconds

Shut off

2 minutes

Shut off

FWD piay the tape A

“TAPE A AG-2”

Fast forward the tape A

“TAPE A AG-3”

REV play the tape A

“TAPE A AG-4”

Rewind the tape A

“TAPE A AG-5”

FWD play the tape B

“TAPE B AG-2”

Fast forward the tape B

“TAPE B AG-3”

REV play the tape B

“TAPE B AG-4”

Rewind the tape B

“TAPE B AG-5”

 “TAPE * AG_*” is display of each step.