- 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 sta-
tic 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-T6740
Page 6: ... 1 5 SPECIFICATIONS ...
Page 7: ... 1 6 MEMO ...
Page 10: ... 2 3 3 FRONT CIRCUIT 1 2 ...
Page 11: ... 2 4 4 FRONT CIRCUIT 2 2 ...
Page 12: ... BLOCK DIAGRAM 2 5 2 6 ...
Page 13: ...2 7 2 8 SCHEMATIC DIAGRAMS FRONT SCHEMATIC DIAGRAM ...
Page 14: ...2 9 2 10 MICOM SCHEMATIC DIAGRAM ...
Page 15: ...2 11 2 12 I O SCHEMATIC DIAGRAM ...
Page 16: ...2 13 2 14 DSP SCHEMATIC DIAGRAM ...
Page 17: ...2 15 2 16 AMP SCHEMATIC DIAGRAM ...
Page 18: ...2 17 2 18 SMPS WIDE SCHEMATIC DIAGRAM ...
Page 19: ...2 19 2 20 POWER SCHEMATIC DIAGRAM ...
Page 20: ...2 21 2 22 WIRING DIAGRAMS ...
Page 21: ...2 23 2 24 PRINTED CIRCUIT DIAGRAMS MAIN P C BOARD COMPONENT SIDE ...
Page 22: ...2 25 2 26 MAIN P C BOARD SOLDER SIDE ...
Page 23: ...2 27 2 28 FRONT P C BOARD SOLDER SIDE FRONT P C BOARD COMPONENT SIDE ...
Page 24: ...2 29 2 30 POWER P C BOARD ...
Page 25: ...2 31 2 32 MEMO MEMO ...
Page 26: ... 3 1 1 Power check flow ELECTRICAL TROUBLESHOOTING GUIDE SECTION 3 DVD PART ...
Page 39: ... 3 14 FIG 7 2 DVD FIG 7 3 CD ...
Page 40: ... 3 15 FIG 7 4 CD FIG 8 1 DVD 8 FOCUS ON W VEFORM ...
Page 41: ... 3 16 FIG 8 2 CD FIG 9 1 9 SPINDLE CONTROL W VEFORM NO DISC CONDITION ...
Page 42: ... 3 17 10 TRACKING CONTROL RELATED SIGNAL System checking FIG 10 1 DVD FIG 10 2 CD ...
Page 44: ... 3 19 ADAT0 3 FIG 12 2 FIG 13 1 2 COMPOSITE VIDEO SIGNAL 13 MT1389 AUDIO OUTPUT TO PWM IC ...
Page 45: ... 3 20 FIG 14 1 14 AUDIO OUTPUT FROM PWM IC ...
Page 50: ...3 25 3 26 DVD PART SCHEMATIC DIAGRAMS MPEG SCHEMATIC DIAGRAM ...
Page 51: ...3 27 3 28 SERVO SCHEMATIC DIAGRAM ...
Page 55: ... 5 2 MODEL LHS T6740C 755 756 757 755 759 758 751 750 752 754 753 752 ...
Page 57: ... 5 4 MEMO ...