DOWNLOAD Panasonic SA-BTT790EE / SC-BTT790EEK Service Manual ↓ Size: 10.92 MB | Pages: 127 in PDF or view online for FREE

5

There are special components used in this equipment which are important for safety.
These parts are marked by (

) in the Schematic Diagrams & Replacement Parts List. It is essential that these critical parts

should be replaced with manufacturer’s specified parts to prevent shock, fire or other hazards. Do not modify the original design
without permission of manufacturer.

6

Some semiconductor (solid state) devices can be damaged easily by static electricity. Such components commonly are called Elec-
trostatically Sensitive (ES) Devices. Examples of typical ES 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 electrostatic discharge (ESD).

1. Immediately before handling any semiconductor component or semiconductor-equipped assembly, drain off any ESD on your

body by touching a known earth ground. Alternatively, obtain and wear a commercially available discharging ESD wrist strap,
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 ES devices, place the assembly on a conductive surface such as alumi-

num foil, to prevent electrostatic charge buildup or exposure of the assembly.

3. Use only a grounded-tip soldering iron to solder or unsolder ES devices.
4. Use only an anti-static solder removal device. Some solder removal devices not classified as “anti-static (ESD protected)” can

generate electrical charge sufficient to damage ES devices.

5. Do not use freon-propelled chemicals.   These can generate electrical charges sufficient to damage ES devices.
6. Do not remove a replacement ES device from its protective package until immediately before you are ready to install it. (Most

replacement ES devices are packaged with leads electrically shorted together by conductive foam, aluminum foil or compara-
ble conductive material).

7. Immediately before removing the protective material from the leads of a replacement ES device, touch the protective material

to the chassis or circuit assembly into which the device will be installed.
Caution:

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 ES 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 (ESD) suf-
ficient to damage an ES device).

7

This product utilizes a laser diode with the unit turned “on”, invisible laser radiation is emitted from the pickup lens.
Wavelength: 790 nm (CDs)/660 nm (DVDs)/405 nm (BDs)
Maximum output radiation power from pickup: 100 

µ

W/VDE

Laser radiation from the pickup unit is safety level, but be sure the followings: 

1. Do not disassemble the pickup unit, since radiation from exposed laser diode is dangerous. 
2. Do not adjust the variable resistor on the pickup unit. It was already adjusted.
3. Do not look at the focus lens using optical instruments.
4. Recommend not to look at pickup lens for a long time.

8

The lead free solder has been used in the mounting process of all electrical components on the printed circuit boards used for this
equipment in considering the globally environmental conservation. 

The normal solder is the alloy of tin (Sn) and lead (Pb). On the other hand, the lead free solder is the alloy mainly consists of tin
(Sn), silver (Ag) and Copper (Cu), and the melting point of the lead free solder is higher approx.30 degrees C (86

°

F) more than that

of the normal solder.

• The lead free solder has to be used when repairing the equipment for which the lead free solder is used.

(Definition: The letter of “PbF” is printed on the PCB using the lead free solder.)

• To put lead free solder, it should be well molten and mixed with the original lead free solder.
• Remove the remaining lead free solder on the PCB cleanly for soldering of the new IC.
• Since the melting point of the lead free solder is higher than that of the normal lead solder, it takes the longer time to melt the

lead free solder.

• Use the soldering iron (more than 70W) equipped with the temperature control after setting the temperature at 350±30 degrees

C (662±86

°

F).

• The following 3 types of lead free solder are available through the service parts route.

RFKZ03D01K-----------(0.3mm 100g Reel)
RFKZ06D01K-----------(0.6mm 100g Reel)
RFKZ10D01K-----------(1.0mm 100g Reel)

* Ingredient: tin (Sn), 96.5%, silver (Ag) 3.0%, Copper (Cu) 0.5%, Cobalt (Co) / Germanium (Ge) 0.1 to 0.3%

The letter of “PbF” is printed either foil side or components side on the PCB using the lead free solder.
 
(See right figure)