20 Most Recent ViewSonic LiteBird PJ875 Multimedia Projector Questions & Answers

If totally dead look at the circuit board at parts after on/off switch. Is there a fuse in one of those immediate lines? Is it open (happens for no reason at times)? And the diodes - any cracked or burnt? Nothing is working so it has to be something all these items have in common. See if you can get a hold of a schematic for unit from manufacturer. Or get a service manual through Google.

If you haven't tried it already, unplug the unit, hold down the power button for 15 seconds, release, then wait about a half hour and try plugging the machine in and powering up again. This may reset the memory and enable your projector to start up normally.

first know the theory as follows ------------------------- Color in DLP projection ----------
The primary methods by which DLP projection systems create a color image, those utilized by single-chip DLP projectors, .----------------
Single-chip projectors In a projector with a single DLP chip, colors are either produced by placing a color wheel between the lamp and the DLP chip or by using individual light sources to produce the primary colors, LEDs for example. The color wheel is divided into multiple sectors: theprimary colors: red, green, and blue, and in many cases secondary colors including cyan, magenta, yellow and white. The use of the secondary colors is part of the new color performance system called BrilliantColor™ which processes the primary colors along with the secondary colors to create a broader spectrum of possible color combinations on the screen.
The DLP chip is synchronized with the rotating motion of the color wheel so that the green component is displayed on the DMD when the green section of the color wheel is in front of the lamp. The same is true for the red, blue and other sections. The colors are thus displayed sequentially at a sufficiently high rate that the observer sees a composite "full color" image. In early models, this was one rotation per frame. Now, most systems operate at up to 10x the frame rate.


ITS A PROBLEM OF COLOUR WHEEL IN YOUR PROJECTOR.THAT WHEEL HAS TO BE REPLACED.CLICK THE LINK FOR ALL THE INSTRUCTIONShttp://www.jangro.com/a/2006/07/24/samsung-dlp-replace-color-wheel/
PLEASE DO NOT FORGET TO ACCEPT THE SOLUTION.
THANK YOU FOR USING FIXYA.
thanks.

Check if there is a cooling fan. Is it rotating? It is also possible that the filter is dusty and needs to be cleaned/replaced. (all projectors have a cooling fan and a filter to prevent dust from reaching the lamp. A faulty fan or a reduced air flow may cause an overheat problem)

Hello, It may be the DMD chip. Do you get the spots on the display even when there is no source connected? Are the spots multiplying? If so, then it is the DMD chip. If it is under warranty, then ship it back. Also, if the projector is less than 5 years old, you could get the chip replaced for free. Some DMD chips have a 5 year warranty that are still good even after the projector's warranty.