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Tube Condition (Wear)

      >> Basic Information 
      >> What Uneven Tube Wear Looks Like On-Screen 
      >> Example of a Poorly Installed Set  
      >> Tube Wear Rating Chart  

What Uneven Tube Wear Looks Like On-Screen


So what does uneven tube wear actually look like up on screen?

Below are screenshots taken from a projector that had uneven tube wear.  This projector (a NEC PG) was installed about 12-14" too far back for most of its life.  It was then moved to the correct location to use the entire tube surface (as should have been done in the first place).  The pictures below are what you would see after the projector was installed at the correct distance. 

The result is clear: The image is pretty much unusable. While  the outside of the image looks good because the tube surface is being used for the first time, the middle of the image is clearly brown in colour due to extreme wear from having the projector installed too far back.

All 3 tubes on:

The second picture (below) with the blue tube turned off. You can see a bit of wear on the green, and the centre of the image is a bit redder than the outside border:

The last picture (below) shows just the blue tube, and clearly shows the wear pattern.  There is significant wear on this blue tube which is causing most of the colour balance problems we're seeing in the overall picture. You could probably just change the blue tube in this case to throw a reasonable picture, but most people would probably want to change both the blue and green (and then hopefully install their newly acquired projector in the right spot!)

So you're stuck with 3 options here:

  • Use the projector 'as is' and live with it.  (Unacceptable to most).
  • Install the projector too far back like the previous installation and try and balance out the colours somewhat, knowing full well that the tubes will continue to wear at an accelerated pace.
  • Replace the worn tubes and install the projector the correct distance from the screen.

We'll let the reader decide which is the only acceptable solution.  :)

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