Safety Instructions, Warnings, and NotesEM5.1E2.EN 5
2. Safety Instructions, Warnings, and Notes
2.1Safety Instructionsstereo sound (L: 3 kHz, R: 1 kHz unless stated otherwise)
and picture carrier at 61.25 MHz (NTSC).
?Where necessary, measure the oscillograms and direct
Safety regulations require that during a repair:
voltages with (symbol D ) and without (symbol E ) aerial
?Connect the Receiver box to the Mains via an isolation
signal. Measure the voltages in the power supply section
transformer.
both in normal operation (symbol G) and in standby
?When you use the Receiver box in combination with a
(symbol F). These values are indicated by means of the
plasma monitor, do not operate the monitor without the
appropriate symbols.
front glass plate. One function of this glass plate is to
?The semiconductors indicated in the circuit diagram and in
absorb IR radiation. Without this glass plate, the level of
the parts lists, are interchangeable position with the
radiation could damage your eyes.
semiconductors in the unit, irrespective of the type
?Safety components, indicated by the symbol h , must be
indication on these semiconductors.
replaced with original components.
Safety regulations require that after a repair, you must return 2.3.2 Schematic Notes
the set in its original condition. Pay particular attention to the
following points:?All resistor values are in ohms and the value multiplier is
?Route the wire trees in their original positions and fix them often used to indicate the decimal point location (e.g. 2K2
in place with the mounted cable clamps.indicates 2.2 kohm).
?Check the insulation of the Mains cord for external ?Resistor values with no multiplier may be indicated with
damage.either an 'E' or an 'R' (e.g. 220E or 220R indicates 220
?Check the electrical DC resistance between the Mains plug ohm).
and the secondary side (only for sets which have a Mains ?All Capacitor values are expressed in Micro-Farads
isolated power supply):(? = x10-6), Nano-Farads (n = x10-9), or Pico-Farads
-12
- Unplug the Mains cord and connect a wire between the (p = x10).
two pins of the Mains plug;?Capacitor values may also use the value multiplier as the
- Set the Mains switch to the "on" position (keep the decimal point indication (e.g. 2p2 indicates 2.2 pF).
Mains cord unplugged!).?An 'asterisk' (*) indicates component usage varies. Refer to
- Measure the resistance value between the pins of the the diversity tables for the correct values.
Mains plug and the metal shielding of the tuner or the ?The correct component values are listed in the Electrical
aerial connection on the set. The reading should be Replacement Parts List. Therefore, always check this list
between 4.5 Mohm and 12 Mohm.when there is any doubt.
- Set the Mains switch to the "off" position, and remove
the wire between the two pins of the Mains plug.2.3.3 Practical Service Precautions
?Check the cabinet for defects, to prevent the customer from
touching any inner parts of the television set.
?It makes sense to avoid exposure to electrical shock.
While some sources are expected to have a possible
2.2Warningsdangerous impact, others of quite high potential are of
limited current and are sometimes held in less regard.
?Always respect voltages. While some may not be
?All ICs and many other semiconductors are susceptible to
dangerous in themselves, they can cause unexpected
electrostatic discharges (ESD symbol w ). Careless
reactions - reactions that are best avoided. Before reaching
handling during repair can reduce life drastically. Make
into a powered TV set, it is best to test the high voltage
sure that, during repair, you are connected with the same
insulation. It is easy to do, and is a good service precaution.
electrical potential as the set by a wristband with
?Before powering up the TV set with the rear cover off
resistance. Keep components and tools at this same
(or on a test fixture), attach a clip lead to the CRT DAG
potential. Available ESD protection equipment:
ground and to a screwdriver blade that has a well insulated
- Complete ESD3 kit (small tablemat, wristband,
handle. After the TV is powered on and high voltage has
connection box, extension cable and earth cable):
developed, probe the anode lead with the blade, starting at
4822 310 10671.
the case of the High Voltage Transformer (flyback - IFT).
- Wristband tester: 4822 344 13999.
Move the blade to within two inches of the connector of the
?Be careful while taking measurements in the live voltage
CRT. If there is an arc, you found it the easy way,
section.
without getting a shock! If there is an arc to the
?Never replace modules, or other components, with the
screwdriver blade, replace the part that is causing the
television set "'ON."
problem: the High Voltage Transformer or the lead (if it is
?Use plastic tools, instead of metal tools, when performing
removable).
alignments on the television set. This will help prevent
short circuits and reduce the danger of a circuit becoming
unstable.
2.3Notes
2.3.1 General
?Measure the direct voltages and oscillograms with regard
to the chassis ground (symbol H), or hot ground
(symbol I).
?The direct voltages and oscillograms shown in the
diagrams are indicative. Measure them in the Service
Default Mode (see chapter 5) with a colour bar signal and |
ACEC
