Causes of problems with projectors - the effect of "color music" and "starry sky"?

Question

Do it yourself

I ask you to tell competent people where to look if projectors, of which there are not so few in the household, in some cases have two drawbacks:
1. Color music - this is how I call the effect of a sharp change in colors during the operation of the projector. This usually happens not immediately, but after a couple of minutes, it looks like a random change in the shades of the image with a very high frequency, which makes it very stressful to look at such a thing.
2. Starry sky - this effect means the appearance of white dots, which are located randomly on the entire image, both at the time of the signal, and without it (an empty system window asking you to connect the video cable).
I heard about two places where you need to look - a lamp and a matrix, but I don’t understand who is responsible for what and can there be a problem in purely pollution, or is it necessary to replace components? I repeat, I ask those who themselves have encountered one of the above effects on the projector and know what helped him / her to answer.

Answer 1

all this is a matrix
and 90% replacement
of white dots - broken pixels
"color music" most likely curved dithering and is not treated except by replacing the projector

Answer 2

If this is a DLP projector, then the DLP chip may be broken (because of this, a starry sky appears and flicker too). This is the sin of little BENQ, Acer and others. In general, I advise you to read about the device of digital projectors.