Alignment And Adjustments; High Voltage Check - Samsung CL25M2MQUX Service Manual

2. Alignment and Adjustments

2-1 General Alignment Instructions
1. Usually, a color TV-VCR needs only slight touch-up
adjustment upon installation.
Check the basic characteristics such as height,
horizontal and vertical sync and focus.
2. Observe the picture for good black and white
details. There should be objectionable color shading;
if color shading is present, demagnetize, perform purity
and convergence adjustments described below.
3. Use the specified test equipment or its equivalent.
4. Correct impedance matching is essential.
2-2 Automatic Degaussing
A degaussing coil is mounted around the picture tube,
so that external degaussing after moving the TV should
be unnecessary. But the receiver must be properly
degaussed upon installation.
The degaussing coil operates for about 1 second after
the power is switched ON. If the set is moved or turned
in a different direction, the power should be OFF for at
least 10 minutes.

2-3 High Voltage Check

CAUTION : There is no high voltage adjustment on this
chassis. The B+ power supply should be +135 volts (with
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 current).
3. Adjust the Brightness and contrast controls to both
extremes. Ensure that the high voltage does not exceed
30 KV under any conditions.
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5. Avoid overload. Excessive signal from a sweep
generator might overload the front-end of the TV.
When inserting signal markers, do not allow the marker
generator to distort test results.
6. Connect the TV only to an AC power source with voltage
and frequency as specified on the backcover ameplate.
7. Do not attempt to connect or disconnect any wires while
the TV is turned on. Make sure that the power cord is
disconnected before replacing any parts.
8. To protect against shock hazard, use an isolation
transformer.
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 turning
power OFF.
If color shading persists, perform the following Color
purity and Convergence adjustments.
Alignment and Adjustments
2-1