Projector to see the text is not clear

I have a 2002 purchase of the projector, the text is now above all do not know what I would like to ask Changsha companies can repair the

Should be the focal length of the problem, try rotating the lens focal length adjustment for the light bulb.Your projector is the antique
a recommendation to you appear 13519121580 revealed the following text is not clear there are a few reasons normally

1.Focal length of the problem

2.Bulb issue

3.Whether there is dust LCD panels (LCD panels limited to the projector)