الأعطال الشائعة في التلفزيون الملون .. كتاب التلفزيون الملون والعادي

20-20 Common faults in color TV:

In a previous chapter we looked at some of the malfunctions of color television. We will now mention some of the common faults that can occur in color receivers.

And we must not lose sight of the fact that color TV contains the phases of monochrome TV - when tracking the faults, we must search and make sure that the picture is in black and white and is it in good condition? If it does not appear in a good condition after closing the color switch, then the fault is likely in the black and white circuits. An exception to this rule may be the presence of a malfunction in the color screen diode or a defect in the voltages that are significant to it.

Manifestations of color screen valve malfunctions:

A - A defect in one of the electronic launchers or the beam will make it impossible to view the image even in black and white, and one of the primary primary colors will be absent.

B - The appearance of sparks or arcs in the picture, especially those that appear when one of the controls is changed or while knocking on the screen - this is due to the presence of an internal short in the color screen valve.

C - The appearance of a faded image in monochrome or color.

D - Changing colors when the device is shaken or knocked.

2 - The monochrome image is normal and there are no colors. The malfunction is due to someone
departments or more, such as:

A - color killer

B - Color sub-carrier oscillator (4.43 MHz).

C - Color pass bandwidth amplifier.

3 - Abnormal color intensity (saturation) See diagram 20 - A - If we assume the integrity of the signal coming from the first amplifier of the visual signal - then the possibility of the fault location is in the pass beam amplifier or in the voltage of the Automatic Color Control (ACC) circuit.

4 - There is no color synchronization - while the synchronization in the mono image is normal. This often causes a defect in the oscillator of the sub-carrier (4.43 MHz) or in the AFPC circuits, i.e. the automatic frequency and page adjustment circuits, and the appearance of the malfunction on the screen is the presence of colored bars.

E - All colors are incorrect - and the monochrome image is good. First, check the position of the color switch - it is possible that the pass-beam amplifier is faulty - or the AFPC system. As well as an oscillator (4.43 MHz).

6- One of the colors is missing, and the monochrome image is normal. Returning to the box diagram, and by observation, the missing color can be identified and counted, and the malfunction is often