Light or Color Spot Issue of an Acer DLP projector

[EmmaStone]

Issue of an Acer DLP projector H6510BD: when i tried to adjust the brightness of the projector a high-brightness spot appears in the middle of the screen. I can eliminate the color spots by editting the brightness or contrast figure, i wanna know if this is an common breakdoen of all DLP projector or a malfunction of this PJ? i have used 3LCD projector and i have never seen this bofore.

 

[Amnesia]

did it still exist when the focus is clearest? under the most blurry contrast, if the dark spots displayed when blurred are more serious than when they are clear, the entire screen is randomly distributed in size, it might because the lens is dirty, maintenance and dust removal can be done, if it is a whole dark spot, it is not excluded The LCD panel is burnt out (LCD projector), or the DMD is broken (DLP projector)