I just set up a nec 6pg xtra according to Guy Kuo's holy focus. It's a very informative set of instructions that gives you a very sharp and clear picture when your done.
My problem is that after running the unit for 2 or 3 hours suddenly the green beam focus just goes out of focus. I undo the cover and reset the focus pot and it's fine for the rest of the movie. The next time I'm watching something, 2 or 3 hours in, the green unfocus again.

Is there some component or board that needs to be checked, it's only the green that this happens on ?

Maybe the F drive is overheating?

How hot does the bottom plate get? Can you add a heatsink and a fan to the bottom plate under the C and F drives?

How hard are you pushing the electronic focus controls?

I'll be closing the unit in soon and put in the proper fans to exhaust the heat. How would I measure or find out about how hard am driving the electronic focus controls ? Kind of new to this stuff.

Make sure the electronic focus is set to ZERO in the menu. Then focus with the pot on the DEF board. Then touch up only. See if it resolves the problem. If not, check the F-drive board.

Yes, they do go bad.

Marc

All the elecronic focus are still at zero,still have not done any of that. Picture looks pretty sharp at the moment. What should I be looking at on the F- drive board ? I did noticed that this problem was happening long before I did this last set-up, the picture was pretty bad so I didn't really care. Now I really notice when that beam changes.