Safety Precautions - Samsung HL67A750A1FXZA Service Manual

1. Precaution
To avoid possible damage, electric shocks or exposure to radiation, follow the instructions below with regard to safety,
installation, service and ESD.
1-1 Safety Precautions
1. Make sure all protective devices are properly installed
including non-metallic handles and compartment covers
when installing or re-installing the chassis or chassis
assemblies.
2. Make sure that no gaps exist between the cabinets for
children to insert their fingers in. To prevent children from
being electrocuted
Errors may occur when the resistance is below 1.0㏁ or
over 5.2㏁. In these cases, make sure that the device is
repaired before sending it back to the customer.
3. Check for Electricity Leakage (Fig. 1-1)
Warning: Do not use an insulated transformer for checking
the leakage. Use only those current leakage testers or
mirroring systems that comply with ANSIC 101.1 and the
Underwriter Laboratory's specifications (UL1410, 59.7).
DEVICE
UNDER
TEST
TEST ALL
EXPOSED METAL
SURFACES
2-WIRE CORD
ALSO TEST WITH
PLUG REVERSED
(USING AC ADAPTER
PLUG AS REQUIRED)
Fig. 1-1 AC Leakage Test
4. A high voltage is maintained within the specified limits using
safety parts, calibration and tolerances. When voltage
exceeds the specified limits, check each special part.
5. Warning for Engineering Changes:
Never make any changes or additions to the circuit design
or the internal part for this product.
Samsung Electronics
(READING SHOULD
LEAKAGE
CURRENT NOT BE ABOVE
0.5mA)
TESTER
EARTH
GROUND
Ex: Do not add any audio or video accessory connectors.
This might cause physical damage. Furthermore, any
changes or additions to the original design/engineering will
invalidate the warranty.
6. Warning - Hot Chassis:
Some TV chassis are directly connected to one end of the
AC power cord for electrical reasons.
Without insulated transformers, the product can only be
repaired safely when the chassis is connected to the
earthed end of the AC power source.
To make sure the AC power cord is properly connected,
follow the instructions below. Use the voltmeter to measure
the voltage between the chassis and the earthed ground. If
the measurement is over 1.0V, unplug the AC power cord
and change the polarity before re-inserting it. Measure the
voltage between the chassis and the ground again.
7. Some TV chassis are shipped with an additional secondary
grounding system. The secondary system is adjacent to the
AC power line. These two grounding systems are separated
in the circuit using an unbreakable/unchangeable insulation
material.
8. When any parts, materials or wirings appear overheated or
damaged, replace them with new regular ones immediately.
When any damage or overheating is detected, correct this
immediately and make a regular check of possible errors.
9. Check for the original shape of the lead, especially that of
the antenna wiring, any sharp edges, the AC power and
the high voltage power. Carefully check if the wiring is too
tight, incorrectly placed or loose. Never change the space
between the part and the printed circuit board. Check the
AC power cord for possible damages. Keep the part or the
lead away from any heat-emitting materials.
Precaution
1-1