Samsung SVR-640, SVR-643, SVR-547, SVR-649, SVR-649-XEV Precautions

IMPORTANT SERVICE GUIDE

◆ MODE SWITCH (PROGRAM SWITCH) ASSEMBLY POINT

1) When installing the ass’y deck on the Main PCB, be sure to align the assembly point of mode switch.

ASSEMBLY POINT

(ALIGN TWO ARROWS)

Fig. 1

◆ HOW TO EJECT THE CASSETTE TAPE
(If the unit does not operate on condition that tape is inserted into housing ass’y)

1) Turn the Gear Worm Πclockwise in the direction of arrow with screw driver. (See Fig. 2)

(Other method ; Remove the screw of Motor Load Ass’y, Separate the Motor Load Ass’y)

2) When Slider S, T are approached in the position of unloading, rotate holder Clutch counterclockwise after inserting screw driver in the

hole of frame’s bottom in order to wind the unwiunded tape. (Refer to Fig. 3)
(If you rotate Gear Worm Πcontinuously when tape is in state of unwinding, you may cause a tape contamination by grease and

tape damage. Be sure to wind the unwiunded tape in the state of set horizontally.)

3) Rotate Gear Worm ˇ clockwise using screw driver again up to the state of eject mode and then pick out the tape. (Refer to Fig. 2)

Fig. 2 Fig. 3

ΠGEAR WORM

FRAME

Samsung Electronics 1-1

1. Precautions

1. Be sure that all of the built-in protective devices are

replaced. Restore any missing protective shields.

2. When reinstalling the chassis and its assemblies, be

sure to restore all protective devices, including :
control knobs and compartment covers.

3. Make sure that there are no cabinet openings

through which people--particularly children

--might insert fingers and contact dangerous
voltages. Such openings include the spacing
between the picture tube and the cabinet mask,
excessively wide cabinet ventilation slots, and
improperly fitted back covers.

If the measured resistance is less than 1.0 megohm
or greater than 5.2 megohms, an abnormality exists
that must be corrected before the unit is returned
to the customer.

4. Leakage Current Hot Check (See Fig. 1-1) :

Warning : Do not use an isolation transformer
during this test. Use a leakage current tester or a
metering system that complies with American
National Standards Institute (ANSI C101.1,
Leakage Current for Appliances), and Underwriters
Laboratories (UL Publication UL1410, 59.7).

5. With the unit completely reassembled, plug the AC

line cord directly the power outlet. With the unit’s
AC switch first in the ON position and then OFF,
measure the current between a known earth
ground (metal water pipe, conduit, etc.) and all
exposed metal parts, including : antennas, handle
brackets, metal cabinets, screwheads and control
shafts. The current measured should not exceed

0.5 milliamp. Reverse the power-plug prongs in the
AC outlet and repeat the test.

6. X-ray Limits :

The picture tube is designed to prohibit X-ray
emissions. To ensure continued X-ray protection,
replace the picture tube only with one that is the
same type as the original.

Fig. 1-1 AC Leakage Test

7. Antenna Cold Check :
With the unit’s AC plug disconnected from the
AC source, connect an electrical jumper across the
two AC prongs. Connect one lead of the ohmmeter
to an AC prong.
Connect the other lead to the coaxial connector.

8. High Voltage Limit :
High voltage must be measured each time
servicing is done on the B+, horizontal deflection
or high voltage circuits.

Heed the high voltage limits. These include the
X-ray protection Specifications Label, and the
Product Safety and X-ray Warning Note on the
service data schematic.

9. Some semiconductor (“solid state”) devices are
easily damaged by static electricity.
Such components are called Electrostatically
Sensitive Devices (ESDs); examples include
integrated circuits and some field-effect transistors.
The following techniques will reduce the
occurrence of component damage caused by static
electricity.

10. Immediately before handling any semiconductor

components or assemblies, drain the electrostatic
charge from your body by touching a known
earth ground. Alternatively, wear a discharging
Wrist-strap device. (Be sure to remove it prior to
applying power--this is an electric shock
precaution.)

DEVICE
UNDER

TEST

(READING SHOULD

NOT BE ABOVE

0.5mA)

LEAKAGE
CURRENT

TESTER

EARTH

GROUND

TEST ALL

EXPOSED METER

SURFACES

ALSO TEST WITH

PLUG REVERSED

(USING AC ADAPTER

PLUG AS REQUIRED)

2-WIRE CORD