I have a Samsung CT5038VC CRT TV, it was showing very well , then suddenly, the entire screen went green! you can still see, but everything is green. Please assist me in finding the solution to this...
Since picture is there, sound also mut be. The screen colour went green is your complaint. It is due to the video output stage of your TV. The fault mainly occur in the picture tube base board card. Loose or bad solderings ara always noted. There are three video output trnsistors there in the base board In some models of Samsung sets, either three individual Ics or one single Ic is used. Anyway the fault lies around this card.
You jsut open your TV, pull out the base card from the picture tube neck, care must be taken when you do, not to shake sideways or up down. Just pull it straight back, otherwise picture tube base pins or picture tube neck wiil get damaged. Before doing this check the vlotages of the three cathode pins of picture tube base. It can be done withoug detaching it out from the neck. There are three cathodes. Blue, Green and Red. In most Tvs these voltage will come near to 130 vdc or so. In your TVs case, now the green cathode voltage will be low with respect to the other two cathodes.
This may be due to a loose soldering or fault related to green cathode itsef. If transistors are used, check the green output transistors collector voltage,and compare it with the other two voltages. If Ics are used, do the same. If one Ic is used the checkings are the same.
Just resolder all the loose suspected points before replacing anything first. If it does't help, you just desolder out the green bias drive, whether it is a transitor, or Ic, whatever may be. If it is transitor, just plug it to the picturetube and switch it on without the green drive. Now you must see a different colour, a mingle of red and blue, a type of cyan. If so you can make sure that green output, whatever type it may be, is faulty. Just replace it with same type and number. Check the 2W resistors, if any used, for open, especially to the green drive transistor load resistor. Ok.
Nov 13, 2010 |
Samsung Standard (CRT) Televisions