Acer :: Aspire 5634 WLMi - Black Images Cause Green Flickering Dots

I have an Acer Aspire 5634WLMi with 2 years. Got a problem on the monitor (15.4-inch LCD CrystalBite).

It slowly started a year ago (at that time still had warranty but underestimated the problem and now it expired). In all the black images(movies, photos) began to appear some green fluorescent dots that looks like they are living (in English I think is called flickering spots, jaggies?!) which then disappear and come back. I did not care at first because both appeared to disappear. Over time there have appeared more, followed by purple dots now. These purple dots are never in black image but sometimes they are the shadow of the black image. But in videos with very dark black only come green dots (always flickering). In all the other colors there is no problem, for example I am writing this in Word and the blue and white of this image is not green. It is however in my opinion a little blurry, I do not know. The letters are black (with a slight green Halo) but it seems that they aren’t standing still and shake a little. The most strange is that on the desktop there is a pattern of green dots on the bottom left and a purple on the upper corner that are often there but sometimes also move around. In fact there was not so long ago a time when I got a perfect image. I began to think that the laptop went to very warm, open a part, cleaned the fan and reduce the processor speed by changing the temperature of the device. After a while it disappeared. But this improvement lasted only 1 day. Then it began all over again. I have also tried to connect the computer to another monitor and had a perfect image, so it seems that it is not the graphics. On the Internet I found many of these reports that the cable that goes from the graphicscard to the monitor is damaged and that a simple substitution leads to full restoration of the notebook. Anyway before attempting to open the laptop (I've been watching some videos of how to do) like to have another opinion from someone who realizes this. I already took him ah repair but wanted 250 euro to replace the monitor with dead pixels (which I think is wrong they are not all dead, and until very squiggly and alternate location). For 250euros rather buy a new though economically not good for me. When the computer has a completely black image is all green. For example when the screensaver comes with the ball moving from one place to another.