I have a Benq DX 650 projector that is about 4 yrs old. It has 1000 hrs on the bulb. Recently while watching a show, a solid blank band showed up across the middle of the screen. It is very uniform and solid. It runs the width of the screen and is about 1/8 of the total size of the projected image. The band is there no matter what input selection I chose and even shows up when I have the blank screen option on. Any idea of what the problem is? When a bulb dies, I'm assuming the whole unit will go dark and not just some of it. Any way I can repair this myself?