Picture turned completely purple
As far as picture and sound is there, your TV has problem at its video output stage. Purple coloured means there is no green emission occur in the picture tube. in otherwords green colour is absent in your TV. This type of fault is related to its video output stage only. Can it be a loose contact or transistor or Ic failure. As your tv is 36" screen size one, you must be cacious to take any repair by yoursef, because its final anode voltage comes around 27KVDC [27,000 VDC], and is dagerous to hold. Anyway I will guide you what to do.
First of all, you just give a small hit with your palm on the top of the cabinet of your TV or its side. Do not use any hard material, only use your hand, and see the colour becomes normal atleast for a second or not. If it comes normal this way, you can make sure that there is some loose soldering occured inside your TV. If it does not help at all, be sure there is some electronic component failure has occured.
If it is so you have to open your TVs back cover, not spoinling anything and cauciously. Keep the power cord of the tv from the wall socket before opening the TV. As you open the TV you first notice a circuit board attached to the base of the picture tube. It is called the base card. It is pluged into it with the help of a socket, and it can be detached from it by slight pull back. You shoud do this very causiouly because picture tube neck, where it is fitted is more thinner than other part of it and it is very nice.
Before pluging out it from the picture tube, keenly notify on its soldered joints for any kind of loose soldering hav or not. There are three cathodes emitting light of three different colours inside the neck of the picture tube. They are Red_Green_and Blue. In your Tv green catode is not emitting any light. Take the voltages of the other two cathodes Red and Blue. Compare this voltage to the voltage now at Green cathode. It will be higher than other two now in your TVs case. Normally all the three cathode voltages should be almost equal to each other, provided a small difference, say 3 to4 VDC is allowable. If the voltage at the Green cathode is found high, it is clear that the transistor or Ic connected as video output of that cathode is out, that is damaged. You should repace the same to make your TVs colour normal.
These are hot services, that is you can oly take voltages of the above mentioned points with your TV pluged into mains votage. All precautions should be taken before attempting anything. Keep children away from you, and let an adult be nearby. Do only if you have confidence and a liitle knowledge about the circutary. Otherwise get the service of an experienced service personal. Ok.
If you feel any difficulty or doubts, inform Fixya about it; they will give me alert.
Oct 21, 2010 |
Proscan PS36125 36" TV