Hello. My name is***** can help you with your question.
The WX model is a very short throw projector. This means that it will produce a given size image and a much closer distance from the screen than a regular projector. For example, with this model you will get a 70 inch diagonal screen at only 7 Foot distance. The image would be extremely dim at a distance of over 10 feet or so. But, if you have used this projector successfully before and you're familiar with the throw distances and it's just not performing like it was before, then it could have something to do with the DLP chip or with the lens. When you replaced the lamp, was it because the previous lamp had gone out completely, or was the previous lamp doing the exact same thing?.
Is possibility that it is simply the bulb that is defective. I'm absolutely certain that you purchased the correct bulb for that projector? While it can be the lens or the DLP chip, a problem with the bulb is more likely. If it is the DLP chip, that is difficult to replace on these projectors. Make sure that the lamp that you bought is Vivitek brand.