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SERVICING PRECAUTIONS
NOTES REGARDING HANDLING OF THE PICK-UP
(1) Notes for transport and storage
1) The pick-up should always be left in its conductive bag until immediately prior to use.
2) The pick-up should never be subjected to external pressure or impact.
Storage in conductive bag
Drop impact
(2) Repair notes
1) The pick-up incorporates a strong magnet, and so should never be brought close to magnetic materials.
2) The pick-up should always be handled correctly and carefully, taking care to avoid external pressure and
impact. If it is subjected to strong pressure or impact, the result may be an operational malfunction and/or
damage to the printed-circuit board.
3) Each and every pick-up is already individually adjusted to a high degree of precision, and for that reason
the adjustment point and installation screws should absolutely never be touched.
4 Laser beams may damage the eyes!
Absolutely never permit laser beams to enter the eyes!
Also NEVER-switch ON the power to the laser output part (lens, etc.) of the pick-up if it is damaged.
NEVER look directly at the laser beam, and don't let
contact fingers or other exposed skin.
5) Cleaning the lens surface
If there is dust on the lens surface, the dust should be cleaned away by using an air bush (such as used
for camera lens). The lens is held by a delicate spring. When cleaning the lens surface, therefore, a
cotton swab should be used, taking care not to distort this.
Pressure
Pressure
How to hold the p
Cotton Swab
Condutive Sheet
6) Never attempt to disassemble the pick-up.
Spring by excess pressure. If the lens is extremely dirty, apply isopropyl alcohol to the cotton swab. (Do
not use any other liquid cleaners, because they will damage the lens.) Take care not to use too much of
this alcohol on the swab, and do not allow the alcohol to get inside the pick-up.
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(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 or humidity is high, where strong
magnetism 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 f rom 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 (1MQ).
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.
Armband
Resistor
(1Mohm)
(' Mohm) - Conductive
Sheet
IMPROVED METHOD -WHEN THE TRAY GEARS WERE DISTORTED
1. How to open the tray.
In case of not suppling power, turn the "D" gear located the bottom of mechanism.
2. How to improve the distorted gears.
(1) Do the hole "C" of the cam gear to face forward the pick-up so the pick-up is down like figure.
_
(2) Da the hole iiBii of main gear to face forward pick-up, too.
(3) Set the last part of main gear to point "A".
(4) Push the tray to end.
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ESD PRECAUTIONS
Electrostatically Sensitive Devices (ESD) -
Some semiconductor (solid state) devices can be damaged easily by static electricity. Such components
commonly are called Electrostatically Sensitive Devices (ESD). Examples of typical ESD devices are integrated
circuits and some field-effect transistors and semiconductor chip components. The following techniques should
be used to help reduce the incidence of component damage caused by static electricity.
1. Immediately before handling any semiconductor component or semiconductor-equipped assembly, drain off
any electrostatic charge on your body by touching a known earth ground. Alternatively, obtain and wear a
commercially available discharging wrist strap device, which should be removed for potential shock reasons
prior to applying power to the unit under test.
2 . After removing an electrical assembly equipped with ESD devices, place the assembly on a conductive
surface such as aluminum foil, to prevent electrostatic charge buildup or exposure of the assembly.
3 . Use only a grounded-tip soldering iron to solder or unsolder ESD devices.
4. Use only an anti-static solder removal device. Some solder removal devices not classified as "anti-static" can
generate electrical charges sufficient to damage ESD devices. -
5 . Do not use freon-propelled chemicals. These can generate electrical charges sufficient to damage ESD
devices.
6 . Do not remove a replacement ESD device from its protective package until immediately before you are ready
to install it. (Most replacement ESD devices are packaged with leads electrically shorted together by
conductive foam, aluminum foil or comparable conductive materials).
7. Immediately before removing the protective material from the leads of a replacement ESD device, touch the
protective material to the chassis or circuit assembly into which the device will be installed.
CAUTION x BE SURE NO POWER IS APPLIED TO THE CHASSIS OR CIRCUIT, AND OBSERVE ALL -
OTHER SAFETY PRECAUTIONS.
8 . Minimize bodily motions when handling unpackaged replacement ESD devices. (Otherwise harmless motion
such as the brushing together of your clothes fabric or the lifting of your foot from a carpeted floor can
generate static electricity sufficient to damage an ESD device).
SPECIFICATIONS
1. Frequency Response (2()Hz_2()kHz) . F
........................................................
t 1 dB
2 . Signal_to_noise Ratio (1 kHz) ..................................................................
g()dB
3 . Dynamic Range (IkHz) .....................................................................
.85dB
4 . T.H.D(~~HZ)~........................................~.....................................O~O~~ .
5 . Channel Separation (1 kHz) ..................................................................
.83dB
6 . power Requirement .................................................
l . Refer to the back panel of unit
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