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HCD-EH25/EH26
2
1. SERVICING NOTES ............................................. 3
2. GENERAL .................................................................. 4
3. DISASSEMBLY
3-1. Disassembly Flow ........................................................... 5
3-2. Rear Cabinet Block ......................................................... 5
3-3. Front Cabinet Block, Top Cabinet Block,
MAIN Board ................................................................... 6
3-4. MF-EH10 (Tape Mechanism Deck), Cassette Lid .......... 6
3-5. Base Unit Block (BU-K8BD90-WOD) .......................... 7
3-6. Optical Pick-up Block (KSM-213CDP) ......................... 7
4. TEST MODE ............................................................ 8
5. MECHANICAL ADJUSTMENTS ...................... 9
6. ELECTRICAL ADJUSTMENTS ........................ 9
7. DIAGRAMS
7-1. Block Diagram - CD SERVO Section - .......................... 12
7-2. Block Diagram - TUNER/USB Section - ....................... 13
7-3. Block Diagram - MAIN/POWER SUPPLY Section - .... 14
7-4. Printed Wiring Board - CD Board - ................................ 16
7-5. Schematic Diagram - CD Board - ................................... 17
7-6. Printed Wiring Board - USB Board - .............................. 18
7-7. Schematic Diagram - USB Board - ................................. 19
7-8. Printed Wiring Board - MAIN Board - ........................... 20
7-9. Schematic Diagram - MAIN Board (1/3) - ..................... 21
7-10. Schematic Diagram - MAIN Board (2/3) - ..................... 22
7-11. Schematic Diagram - MAIN Board (3/3) - ..................... 23
7-12. Printed Wiring Board - PANEL Board - ......................... 24
7-13. Schematic Diagram - PANEL Board - ............................ 25
7-14. Printed Wiring Board - PT-VBUS Board - ..................... 26
7-15. Schematic Diagram - PT-VBUS Board - ........................ 26
8. EXPLODED VIEWS
8-1. Overall Section ............................................................... 27
8-2. Front Cabinet Section ..................................................... 28
8-3. Top Cabinet Section ........................................................ 29
8-4. Base Unit Section (BU-K8BD90-WOD) ........................ 30
9. ELECTRICAL PARTS LIST .............................. 43
Accessories are given in the last of the electrical parts list.
TABLE OF CONTENTS NOTES ON CHIP COMPONENT REPLACEMENT
- Never reuse a disconnected chip component.
- Notice that the minus side of a tantalum capacitor may be dam-
aged by heat.
SAFETY-RELATED COMPONET WARNING!
COMPONENTS IDENTIFIED BY MARK 0 OR DOTTED LINE
WITH MARK 0 ON THE SCHEMATIC DIAGRAMS AND IN
THE PARTS LIST ARE CRITICAL TO SAFE OPERATION.
REPLACE THESE COMPONENTS WITH SONY PARTS
WHOSE PART NUMBERS APPEAR AS SHOWN IN THIS
MANUAL OR IN SUPPLEMENTS PUBLISHED BY SONY. CAUTION
Use of controls or adjustments or performance of procedures
other than those speci
fi ed herein may result in hazardous radia-
tion exposure.
This appliance is classifi ed as
a CLASS 1 LASER product.
This marking is located on the
rear exterior.
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HCD-EH25/EH26
3
SECTION 1
SERVICING NOTES
NOTES ON HANDLING THE OPTICAL PICK-UP
BLOCK OR BASE UNIT
The laser diode in the optical pick-up block may suffer electrostat-
ic 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 fl exible board is easily damaged and should be handled with
care.
NOTES ON LASER DIODE EMISSION CHECK
The laser beam on this model is concentrated so as to be focused
on the disc re fl ective surface by the objective lens in the optical
pickup block. Therefore, when checking the laser diode emission,
observe from more than 30 cm away from the objective lens.
UNLEADED SOLDER
Boards requiring use of unleaded solder are printed with the lead-
free mark (LF) indicating the solder contains no lead.
(Caution: Some printed circuit boards may not come printed with the lead free mark due to their particular size)
: LEAD FREE MARK
Unleaded solder has the following characteristics.
- Unleaded solder melts at a temperature about 40 °C higher than ordinary solder.
Ordinary soldering irons can be used but the iron tip has to be applied to the solder joint for a slightly longer time.
Soldering irons using a temperature regulator should be set to about 350 °C.
Caution: The printed pattern (copper foil) may peel away if the heated tip is applied for too long, so be careful!
- Strong viscosity
Unleaded solder is more viscous (sticky, less prone to fl ow)
than ordinary solder so use caution not to let solder bridges
occur such as on IC pins, etc.
- Usable with ordinary solder
It is best to use only unleaded solder but unleaded solder may also be added to ordinary solder.
Model POWER VOLTAGE INDICATION
AEP, UK and Russian
models AC 230 V, 50/60 Hz
Korean model AC 220 V, 60 Hz
MODEL IDENTIFICATION
LASER DIODE AND FOCUS SEARCH OPERATION
CHECK
During normal operation of the equipment, emission of the laser
diode is prohibited unless the upper lid is closed while turning on
the SW750. (push switch type)
The following checking method for the laser diode is operable.
- Method
Emission of the laser diode is visually checked. 1. Open the upper lid.
2. Push the SW750 as shown in Fig.1.
Note: Do not push the detection lever strongly, or it may be bent or dam-
aged.
3. Check the object lens for con fi rming normal emission of the
laser diode. If not enitting, there is a trouble in the automatic
power control cirsuit or the optical pick-up.
In this operation, the object lens will move up and down 2 times along with inward motion for the focus search.
SW750
Fig.1 Method to push the SW750
Power Voltage
Indication
- Rear Cabinet -
