1-3
NOTES REGARDING COMPACT DISC PLAYER REPAIRS
1. Preparations
1) Compact disc players incorporate a great many ICs as well as the pick-up (laser diode). These components
are sensitive to, and easily affected by, static electricity. If such static electricity is high voltage, components
can be damaged, and for that reason components should be handled with care.
2) The pick-up is composed of many optical components and other high-precision components. Care must be
taken, therefore, to avoid repair or storage where the temperature of humidity is high, where strong magnet-
ism is present, or where there is excessive dust.
2. Notes for repair
1) Before replacing a component part, first disconnect the power supply lead wire from the unit
2) All equipment, measuring instruments and tools must be grounded.
3) The workbench should be covered with a conductive sheet and grounded.
When removing the laser pick-up from its conductive bag, do not place the pick-up on the bag. (This is
because there is the possibility of damage by static electricity.)
4) To prevent AC leakage, the metal part of the soldering iron should be grounded.
5) Workers should be grounded by an armband (1M
Ω
)
6) Care should be taken not to permit the laser pick-up to come in contact with clothing, in order to prevent
static electricity changes in the clothing to escape from the armband.
7) The laser beam from the pick-up should NEVER be directly facing the eyes or bare skin.
Resistor
(1 Mohm)
Conductive
Sheet
Resistor
(1 Mohm)
Armband
Summary of Contents for LH-T255SD
Page 7: ......
Page 8: ...2 1 SECTION 2 AUDIO PART AUDIO TROUBLESHOOTING GUIDE 1 POWER SUPPLY CIRCUIT ...
Page 9: ...2 2 2 FRONT CIRCUIT 1 2 PIN3 PIN4 PIN9 27 5 FL 32 4 VKK 23 7 FL 5 0 CN902 CN902 ...
Page 10: ...2 3 3 FRONT CIRCUIT 2 2 ...
Page 11: ......
Page 14: ...2 8 2 9 2 POWER SUB SCHEMATIC DIAGRAM A B C D E F G H I J K L M N O P Q R S T ...
Page 15: ...2 10 2 11 3 MICOM SCHEMATIC DIAGRAM A B C D E F G H I J K L M N O P Q R S T ...
Page 16: ...2 12 2 13 4 FRONT SCHEMATIC DIAGRAM A B C D E F G H I J K L M N O P Q R S T ...
Page 17: ...2 14 2 15 5 DSP AMP SCHEMATIC DIAGRAM A B C D E F G H I J K L M N O P Q R S T ...
Page 18: ...2 16 2 17 6 I O SCHEMATIC DIAGRAM A B C D E F G H I J K L M N O P Q R S T ...
Page 19: ...2 18 2 19 7 MAIN MIC SCHEMATIC DIAGRAM A B C D E F G H I J K L M N O P Q R S T ...
Page 21: ...2 22 2 23 PRINTED CIRCUIT BOARD DIAGRAMS 1 MAIN DVD P C BOARD DIAGRAM TOP ...
Page 22: ...2 24 2 25 2 MAIN DVD P C BOARD DIAGRAM BOTTOM ...
Page 23: ...2 26 2 27 3 FRONT P C BOARD ...
Page 25: ......
Page 28: ...3 3 A 115 ...
Page 29: ...3 4 B 1 2 ...
Page 30: ...3 5 C ES6698 ES6698 ES6698 ...
Page 31: ...3 6 D ...
Page 47: ......
Page 49: ...A B C D E F G H I J K L M N O P Q R S T 3 24 3 25 2 RF SERVO SCHEMATIC DIAGRAM ...
Page 50: ...3 FRONT MIC SCHEMATIC DIAGRAM A B C D E F G H I J K L M N O P Q R S T 3 26 3 27 ...
Page 51: ......
Page 54: ...5 1 SECTION 5 SPEAKER SECTION MODEL LHS 25SDS 852 853 851 850 854 A800 ...
Page 55: ...5 2 MODEL LHS 25SDW A900 953 954 955 956 958 957 950 ...