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Safety Precaution; General Information; Automatic Degaussing - Magnum CTV-2120 TXT Service Manual

Tv set

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In this TV unit, IC801 is the main chip while IC802, IC201 and other chips are regarded as sub-chips.
2.1
IC801 (CPU) controls the functions of IC201 via the I
2.2 The data of channel positions, BT voltage, band, AFT, clear, volume, power on/off, timer, color, etc. are written
into, stored in and read out from IC802 via the I

SAFETY PRECAUTION

1. High voltage of 24-26 kV is always present inside this receiver when it is operating, so be cautious of electric shock
hazard while removing the back cabinet to process adjustment.
(A) Servicing should not be attempted by any person who is not very familiar with the required re-cautions when
working on this high-voltage equipment.
(B) Before removing the anode cap of the picture tube, discharge the high voltage potential from the picture tube
anode several times by short-circuiting the anode together with its ground to keep off electric shock hazard.
(C) Perfectly discharge the high voltage potential of the picture tube before handling the picture tube which is
highly evacuated. When it is broken, danger may be caused because of the violent burst of its glass fragments.
2. If the fuse in this receiver is blown, replace it with the type specified in the chassis parts list or with the same
specifications (never use other types).
3. Whenever replacing with new components, twist the lead wires of the component together with the concerned
residual leads before soldering.
4. Whenever replacing with a new high wattage resistor (such as oxide metal film resistor) on any of the circuit boards,
keep the body of the resistor 10 mm above the circuit board.
5. Keep all connecting wires away from the components of high voltage or high temperature.
6. This receiver is designed to operate at AC 175-245V~50/60Hz, NEVER connect to DC supply or any other power
sources.
7. The main chassis of this receiver is perfectly isolated.
INSTALLATION AND SERVICE ADJUSTMENTS

GENERAL INFORMATION:

Normally, this receiver have been thoroughly checked and adjusted before leaving the factory; therefore it should
operate normally and produce perfect color and B/W pictures upon installation. However, several minor adjustments
may be required according to the practical situation.
This receiver is packed in a cardboard carton during transportation. Carefully draw it out from the carton and remove
all packing materials.
Plug the receiver's power cord into a convenient 175-245V 50/60Hz AC two pins or three pins power outlet.
Check and adjust all the customer controls such as BRIGHTNESS, CONTRAST and COLOUR to obtain natural color or
B/W picture.

AUTOMATIC DEGAUSSING :

A degaussing coil is mounted around the picture tube so that external degaussing after moving the receiver is
normally unnecessary, providing the receiver is properly degaussed upon installation. The degaussing coil operates for
about 1 second after the power to the receiver is switched ON. If the set is moved or faced in a different direction, the
power switch must be switched off at least one hour in order that the automatic degaussing circuit operates properly.
And then the receiver turned it again.
Should the chassis or parts of the cabinet become magnetized to cause poor colour purity, use an external degaussing
coil. Slowly move the degaussing coil around the faceplate of the picture tube, the sides and front of the receiver and
slowly withdraw the coil to a distance of about 2 meters before disconnecting it from AC source. If colour shading still
persists, perform the "COLOUR PURITY ADJUSTMENT" and "CONVERGENCE ADJUSTMENTS" procedures as
mentioned later.
S D A
SCL
S D A
S C L
2
C bus.
SDA
SCL
2
C bus between them.
3

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