Important Notice For Service Personnel Before Servicing; Safety Precaution - Samsung MP5671 Service Manual

• IMPORTANT NOTICE FOR SERVICE PERSONNEL BEFORE SERVICING
PLEASE READ BEFORE ATTEMPTING SERVICE
1.
Line voltage must be kept within ±10% of the rated
voltage.
2. When operating at line voltage, confirm the DC
voltage at GT4 is 75V ± 0.5V (Adjust VR603).
3. DO NOT DISCHARGE, ARC, OR MEASURE HIGH
VOLTAGE WHEN HIGH VOLTAGE LEAD IS CON-
NECTED TO CRT. DISCHARGE 2ND ANODE OF
CRT ONLY AFTER HIGH VOLTAGE LEAD HAS
BEEN DISCONNECTED. DO NOT DISCHARGE
HIGH VOLTAGE LEAD AT ANY TIME, DAMAGE
TO COMPONENTS MAY RESULT.
4. While the monitor is in operation, do not attempt to
connect or disconnect any wires.
5. Disconnect all power before attempting any repairs.
6. When the power is on, do not attempt to short any
portion of the circuit. This shorting may cause
damage to the components of the circuits.
• SAFETY PRECAUTION
WARNING:
Service should not be attempted by anyone unfamiliar with the necessary precautions on this unit. The
following precautions are necessary during servicing.
1. Some parts such as a picture tube in this unit have
special safety-related characteristics for X-RAY
RADIATION protection. For continued safety, the
parts replacement should be undertaken referring to
item 2 below.
2. Many electrical and mechanical parts in this unit have
special safety-related characteristics for protection
against shock hazard, fire hazard and others. These
characteristics are often passe9 unnoticed by a visual
inspection and the protection afforded by them
cannot necessarily be obtained by using replacement
components rated for higher voltage wattage, etc.
Replacement parts which have these special safety
characteristics are identified in this manual and its
supplements by shading on the schematic diagram
and the parts list. Before replacing any of these com-
ponents, read the parts list in this manual carefully.
3. When replacing a chassis in the cabinet, always be
certain that all the protective devices are installed
properly, such as insulating covers, barriers, strain
relief, etc.
4. Before replacing the back cover of the set, thoroughly
inspect inside the cabinet to set that no stray parts or
tools have been left inside.
5. Before returning the set to the customer, always
perform an AC leakage current check on the exposed
metallic parts of the cabinet, such as terminal, screw-
heads, metal overlays, control shafts, etc. to be sure
the set is safe to operate without danger of electrical
shock. Plug the AC line cord directly into a 120V AC
3
outlet (do not use a line isolation transformer during
this check). Use an AC voltmeter having 5000 ohms
per volt or more sensitivity in the following manner.
Connect a 1500 ohm, 10 watt resistor, paralleled by a
0.15J.lF, 250V AC capacitor, between a known good
earth ground· (water pipe, conduct, etc.) and the
exposed metallic parts, one at a time. Measure the AC
voltage across the combination of 1500 ohm resistor
and 0.15J.lF capacitor. Reverse the AC plug at the AC
outlet and repeat AC voltage measurements for each
exposed metallic part. Voltage measured must not
exceed 0.3 volts RMS. This corresponds to O.2mA AC.
Any value exceeding this limit constitutes a potential
shock hazard and must be corrected immediately.
AC VOLTMETER
(HAVING 1000n/V,
OR MORE SENSITIVITY)
O.151'F AC·TYPE
PLACE THIS PROBE
f-----..L-...... ...-J'INI.r_~ ......
ON EAC H EX POS E D
METAL PART
GOOD EARTH GROUND