I read another post on another website. The writer had the same problem. He mentioned that he believed the color wheel had gotten out of balance. (I have no idea if he even knows what he talking about). He had tapped his machine and then no white line. I remembered that when I had started the projector the last time there was no white line. Then someone wanted the projector tipped up more that the front post would allow and put a book under the front of the projector. Soon we had a white line. Don't know if this was coincidence or not. I set up my machine yesterday on a level surface (without elevating the front post). It still had the white line. I tapped the machine lightly and the line went away and did not come back during the next 45 minutes of use. I don't believe it is "fixed" but wonder about main board failure if a tap could "fix" the problem. Any further ideas? Could there be a loose connection? Years ago we were having trouble with our vertical hold on our TV. It was under warrantee and the repairman told us that that particular model had a problem with some poor solder connections. He soldered a few and tested all and they worked. About 6 months later, the same problem. He came out again and soldered the rest of the connections. The TV has not given us any problem since. I know others have complained about this problem. Has Optoma looked into this that you know of? Anyway, thanks for your quick response and help.

Office Equipment & Supplies - Optoma - EP719 XGA DLP PROJECTOR 2000L 2500:1 CONT DVI-D WITH HDCP...