I'm very sorry for any inconvenience this may have caused you. Unfortunately, this sounds like it may need servicing. Here's the thread where you can get details on setting that up: http://forums.cnet.com/7723-13973_102-542437/service-issues-click-here-for-help/
I have a 8 years old HLR6168WX DLP TV. When turn on power, the TV has no picture (or screen split to 2 half) for about 5-10 minutes. After that it works fine. I've changed lamp and color wheel, but these do not help. This problem only happens on cool start.