Hi All,
Just wanted to provide a possible solution to this problem...
I bought an Optoma HD20 about a year ago (refurbed). The bulb obviously wasn't new because it went after 700 hours or so. I replaced the bulb tonight, but when I turned it on there were double white vertical lines running up and down the screen... When I tried pushing on the top, they would sometimes change a little bit, but wouldn't go away. I tried fiddling with it for an hour and then some, but nothing changed. Since pushing on the top seemed to affect it, I pulled removed the top to take a look and what I was pushing on.
The board that was under where i was pushing has a metal cover over it and appeared to be the main board. I unplugged the connectors from the board and removed the numerous screws. The board also houses the video connectors and such on the back, and the while plastic panel comes out with it. I pulled the board straight up slowly and removed it. On the bottom of the board is a long slide on connector with many pins, like you'd see on a nintendo or sega genesis cartridge.
I figured if I was pushing on the top, I would have been putting pressure downwards on this connector when I was pushing on the top, so I took a qtip and some isopropyl alcohol and cleaned the metal leads on it. Then I made sure there was no dust or fibers on the connector, seated the board back in place and put it all back together...
Viola! No more lines, just a nice clean image! I'm assuming this fix won't work for everyone, say if the board itself has a failure, but the PJ is working flawlessly now. I was trying to get it to work for at least an hour previously with the only changes being mostly for the worse (more lines that would get better if I pushed on the top sometimes), but now I've been running it for several hours with no signs of trouble.
If you're not comfortable pulling apart electronic devices, I wouldn't recommend doing this. It's not complicated, but there are things that I can see would break if you put too much force on them. I also strongly recommend avoiding touching components on the board and making sure you're grounded. Not too much chance for trouble if you're careful, but a grounding strap wouldn't be a bad idea. Wouldn't want to turn a possible free fix into a non warranty repair bill!
Anyhow, just giving a possible solution to some people's problems. Good luck!
-Gary