Tip & How-To about Televison & Video
The fault is mainly due to the video output section of the TV. The video output section can be located at the neck of the picture tube. The board that directly plugged on to the neck of the picture tube is its video output board, which can be detached out from the neck of the picture tube, by a straight backward pull.. Pull it straight forward, don't make any sideward or upward downward motion, as it may damage the connection pins of the picture tube. There are some hi-watt resistors and video output transistors,[ 3 of them to amplify three primary colors]. In some sets, this section will be composed of an IC. If ic is used, there will be no transistors at all. The most common problem for lose of one primary color to this type sets are loose solder points. The components in the video output section will heat up while working. Repeated heating and cooling may make the solder terminals of these components to get loose contacted.
Normally, some of these loose solder points are very minute, microscopic, to detect by normal vision. Some of them can be detected. Just do what we service technicians do, when we come across this kind of fault at service table. Just resolder most of the suspected solder terminals, by applying a little more solder to each point, without making any solder bridge short in between adjacent solder terminals. This must solve the problem.
If not, check the strip wire connection terminals that comes from the main board to this video output board at the picture tube base for any loose contact. Check its other end too, which is connected to the main board. These wires are the carriers of the RGB signal voltages. If there is some loose with this wire contacts, or a break in this strip wire, also may the cause of this primary color loss problem.
If there are no problems as said above, the chroma IC is faulty. There is no other way than replace it with same type and number.
Posted by The Knight... on
Sep 16, 2011 | Sony FD Trinitron WEGA KV-27FS100 27" TV
Dec 20, 2010 | Samsung CSN2077 20 in. TV/DVD Combo
Nov 17, 2010 | JVC AV-32D305 32" TV
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