Samsung CT566BVX/STR, Руководство по обслуживанию

Страница: 16 / 66

3-3-2 Automatic Degaussing
A degaussing coil is mounted around the pic-
ture tube, so external degaussing after moving
the TV should be unnecessary. However, the
receiver must be properly degaussed upon
installation.
The degaussing coil operates for about 1 sec-
ond after the power is switched ON. If the set
has been moved or turned in a different direc-
tion, disconnect its AC power for at least 10
Minutes.
If the chassis or parts of the cabinet become
magnetized, poor color purity will result. If
this happens, use an external degaussing coil.
Slowly move the degaussing coil around the
faceplate of the picture tube and the sides and
front of the receiver. Slowly withdraw the coil
to a distance of about 6 feet before removing
power.
3-3-3 High Voltage Check
CAUTION : There is no high voltage adjust-
ment on this chassis. The B+ power supply
must be set to 135V or +125V (for 20Ó
screen). Conditions : Full color bar input and
normal picture level.
1. Connect a digital voltmeter to the second
anode of the picture tube.
2. Turn on the TV. Set the Brightness and
Contrast controls to minimum (zero beam cur-
rent).
3. The high voltage must not exceed 29.5KV.
4. Adjust the Brightness and Contrast controls to
both extremes. Ensure that the high voltage
does not exceed 29.5KV under any conditions.
3-3-4 FOCUS Adjustment
1. Input a black and white signal.
2. Adjust the tuning control for the clearest pic-
ture.
3. Adjust the FOCUS control for well defined
scanning lines in the center area of the screen.
3-3-5 B + Line Check
There are 3 power modes :
1. ÒAÓ : When AC power supply is connected ;
Ò Stand-ByÓ mode.
2. ÒBÓ : When Ò Set Power-ONÓ button is
pressed.
3. ÒCÓ : Driven by FBT.
Each voltage is marked on its lead-in wire.
( )
3-3-6 F/S (Fail Safe) Circuit Check
1. The failsafe circuit check is the final step after
servicing.
2. Turn the power switch on and adjust the
screen for ÒNormalÓ.
3. Temporarily short Pin R and Pin X on the
chassis (RX05, RX04). Sound and picture will
disappear.
4. The TV should remain in this state. This
shows that the failsafe circuit is working prop-
erly.
5. To restore picture and sound, temporarily turn
off the AC power supply. After about 30 sec-
onds, switch power ON.
21”+ 1
27.5KV
25”
29.5KV
29”
29.5KV
29” + 1
29.5KV
SIZE
MAX
H-VOLTAGE
Alignment and Adjustments
Samsung Electronics 3-7
_
_