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– 5 –

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2

...............................................

6

................................................................... 13

......................................................... 15

.............................................................. 27

......................... 32

6-1. Block Diagram  – CD SERVO Section – ....................... 41
6-2. Block Diagram  – MD SERVO Section (1/2) – ............. 43
6-3. Block Diagram  – MD SERVO Section (2/2) – ............. 45
6-4. Block Diagram

– DISPLAY/POWER SUPPLY Section – ...................... 47

6-5. Note for Printed Wiring Boards and

Schematic Diagrams ....................................................... 50

6-6. Printed Wiring Board  – BD (CD) Section – .................. 51
6-7. Schematic Diagram  – BD (CD) Section – .................... 53
6-8. Printed Wiring Boards

– CD MOTOR/SENSOR Section – ................................ 55

6-9. Schematic Diagram

– CD MOTOR/SENSOR Section – ................................ 57

6-10. Schematic Diagram  – BD (MD) Section (1/2) – ........... 59
6-11. Schematic Diagram  – BD (MD) Section (2/2) – ........... 61
6-12. Printed Wiring Board  – BD (MD) Section – ................. 63
6-13. Printed Wiring Boards

– MD MOTOR/SENSOR Section – ............................... 67

6-14. Schematic Diagram

– MD MOTOR/SENSOR Section – ............................... 69

6-15. Printed Wiring Board

– MICROCOMPUTER Section – ................................... 71

6-16. Schematic Diagram

– MICROCOMPUTER Section – ................................... 73

6-17. Printed Wiring Boards  – RELAY Section – .................. 75
6-18. Schematic Diagram  – RELAY Section – ...................... 77
6-19. Printed Wiring Board  – MAIN Section – ...................... 79
6-20. Schematic Diagram  – MAIN Section – ......................... 81
6-21. Printed Wiring Boards  – CD JOG/SW Section – .......... 83
6-22. Schematic Diagram  – CD JOG/SW Section – .............. 85
6-23. Printed Wiring Board  – CD DISPLAY Section – ......... 87
6-24. Schematic Diagram  – CD DISPLAY Section – ............ 89
6-25. Printed Wiring Boards  – MD JOG/SW Section – ......... 91
6-26. Schematic Diagram  – MD JOG/SW Section – ............. 93
6-27. Printed Wiring Board  – MD DISPLAY Section – ........ 95
6-28. Schematic Diagram  – MD DISPLAY Section – ........... 97
6-29. IC Pin Function Description ......................................... 105

.............................................. 116

............................. 125

– 6 –

The laser diode in the optical pick-up block may suffer electro-
static 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 emis-
sion, observe from more than 30 cm away from the objective lens.

Carry out the “S curve check” in “CD section adjustment” and
check that the S curve waveforms is output three times.

• Never reuse a disconnected chip component.
• Notice that the minus side of a tantalum capacitor may be dam-

aged by heat.

• Keep the temperature of the soldering iron around 270 ˚C dur-

ing repairing.

• Do not touch the soldering iron on the same conductor of the

circuit board. (within 3 times)

• Be careful not to apply force on the conductor when soldering

or unsoldering.

Note:
Be sure to connect all wires (including FFC) in the MD
section before applying power or ICs may be damaged.

CAUTION

Use of controls or adjustments or performance of procedures
other than those specified herein may result in hazardous ra-
diation exposure.

This appliance is classified as a CLASS 1 LASER product.
The CLASS 1 LASER PRODUCT MARKING is located on
the rear exterior.

Laser component in this product is capable of emitting radiation
exceeding the limit for Class 1.

The following caution label is located inside the unit.

!

– 7 –

• As this set has not own power supply, it does not operate inde-

pendently. Therefore, during servicing, connect it to the Pre-
Main amplifier and Tuner Unit (STR-MD777) of DHC-MD777.

If STR-MD777 are not available, use the Power Feed Jig (PFJ-
1) and Relay Connector Jig.
In this case, after turn on the POWER switch on the Power Feed
Jig, supply power with the following methods.

Press the

[REPEAT]

and

[1/ALL]

buttons simultaneously.

(Power is turned off, when press the

[CLEAR]

and

[1/ALL]

button simultaneously)

Insert the disc in the any MD disc slot.

 Enter the test mode, when Insert the disc while pressing

the both

[ENTER/YES]

and

π buttons

(or

[ENTER/YES]

button only).

Set

SYSTEM CONTROL terminal

SYSTEM CONTROL terminal

Connector cable (15P)

Pre-Main AMP
and Tuner Unit

AC IN

Relay connector jig
(J-2501-166-A)

FH-E939,838,737
MHC-6600,5600,
3600,2600
CDP/TC

CN103

CN201 (15P)
SYSTEM CONTROL terminal

Set

Connector cable

CN102

FH-E828
FH-E929

MHC-2300
MHC-3500
MHC-5500

ST

Power feed jig
(PFJ-1)

17P

15P

– 8 –

The IOP value labeled on the pick-up can be recorded in the non-volatile memory. By recording the value, it will eliminate the need to look
at the value on the label of the optical pick-up. When replacing the pick-up or non-volatile memory (IC171 on BD (MD) board), record the
IOP value on the pick-up according to the following procedure.

Record Precedure:
1. Enter the test mode. (See the “SECTION 5 TEST MODE” for detail of test mode)
2. Turn the

≠

↔

± dial to display “[Service]”, and press the

[ENTER/YES]

button.

3. Turn the

≠

↔

± dial to display “lop.Write” (C28), and press the

[ENTER/YES]

button.

4. The display becomes “Ref=@@@.@” (@ is an arbitrary number) and the numbers which can be changed will blink.
5. Input the IOP value written on the optical pick-up.

To select the number: Turn the

≠

↔

± dial.

To select the digit

: Press the

[MD WALKMAN SYNC]

button.

6. When the

[ENTER/YES]

button is pressed, the display becomes “Measu=@@@.@” (@ is an arbitrary number).

7. As the adjustment results are recorded for the step 6. value. Leave it as it is and press the

[ENTER/YES]

button.

8. “Complete!” will be displayed momentarily. The value will be recorded in the non-volatile memory and the display will become “Iop

Write”.

9. Press the

[REPEAT]

button to complete, and the set returns to normal mode.

Display Precedure:
1. Enter the test mode. (See the “SECTION 5 TEST MODE” for detail of test mode)
2. Turn the

≠

↔

± dial to display “[Service]”, and press the

[ENTER/YES]

button.

3. Turn the

≠

↔

± dial to display “Iop Read” (C27).

4. Press the

[ENTER/YES]

button. “@@.@/##.#” is displayed and the recorded contents are displayed.

@@.@ : indicates the Iop value labeled on the pick-up.
##.#

: indicates the Iop value after adjustment

5. To end, press the

[MENU/NO]

button to display “Iop Read”. Then press the

[REPEAT]

button, and the set returns to normal mode.

This mode is test for fluorescent indicator tube, LED, buttons and jog dial.
This mode can not exit in the middle of the test, therefore finish the test when enter this mode.

Fluorescent Indicator Tube and Buttons Test Mode
1. While pressing the both

[ENTER/YES]

and

[REC]

buttons, turn the power ON.

2. After display “FL AllOn key”, lights up all segments on fluorescent indicator tube immediately.
3. Press every buttons of except

[MD WALKMAN SYNC]

button on the MD section, then each segment goes off and remain the “L-

SYNC”.

4. Press the

[MD WALKMAN SYNC]

button to display “Push YES”.

5. Press the

[ENTER/YES]

button and switch over to next check mode “5x7 Segments on Fluorescent Indicator Tube check”.

1. After display “Seg Chk”, 5x7 segments part changes to display mesh pattern immediately.
2. Press the

[ENTER/YES]

button to display “Jog & LED”, and switch over to next check mode “JOG & LED Check”.

1. Each time the

≠

↔

± dial is turned,

[MD WALKMAN SYNC]

LED lights on/off and

[MD1-5]

LED color changes into green/

amber.

2. Press the

[ENTER/YES]

button to display “Check End!”.

Press the

[ENTER/YES]

button: Exit to “Display Test Mode” and enter the other test mode.

Press the

[MENU/NO]

button : Repeat the “Display Test Mode”