Home Theater sales, calibration, service, and discussion forum. Hundreds of free manuals & setup tips.

Sign up and receive the latest newsletters by email!     Join the Forum discussions!    
    Site Map  
Home Products
For Sale
Links Contact
CRT Primer
Troubleshooting Tips
Mounting Methods
Definitive CRT
Projector Setup Guide
Tube/Raster Setup
Tube Condition (Wear)
Projector Rankings
Video Processors
Ampro 1500/2000
Ampro 2300/2600
Ampro 3600/4600
Barco (Older Analog)
Barco 70x/Cine7  
Barco 500/800/801
Barco 808/Cine8
Barco 120x/Cine9
Dwin 500/700
Electrohome ECP 
Electrohome Marquee 
Panasonic 108x
Sony 10xx
Sony 125x/127x
Sony 1292
Sony D50
Sony G70
Sony G90
Zenith 841/851
Zenith 895/900
Zenith 1200

Conditioning Rebuilt Tubes


Back to Advanced Procedures Index


The following procedure was written by Curt Palme. 

When you buy a rebuilt tube from VDC, the tube needs to be conditioned. It’s also a good idea to do this when you buy a new tube, but my understanding is that Sony and Panasonic already do this. It can’t hurt to do it again.

A tube needs to be conditioned as the phosphor has not properly cured when it’s sprayed on the tube. If you start using the rebuilt tube without hardening the phosphor, premature browning of the phosphor will occur in as low as 200 hours. What’s needed is an all white field put on the face of the tube which will raise the temperature of the phosphor and it will harden so it can be used normally without discoloration.

Here are the steps to successfully condition a tube:

Note:  Be aware that this is a slow process and requires 4 days (96 hours) to complete correctly.  Shortcuts are not possible here!

1) Set your system up so that a DVD signal is running into the projector with at least a 480p resolution. You don’t want to use 480i, as the scanning lines will be too obvious on the face of the tube, and can wear into the face of the tube during the conditioning process. You want to run at least 480p or line doubling.

2) If you don’t already have this, you’ll need an AVIA test DVD that can display an all white pattern (100IRE) or a PC with an all-white screen test pattern (make sure to turn off your screensaver!).

3) Max out your height and width to 100% or maximum within the menus or controls in your projector. If your raster now spills over the edge of the tube, you’ll be fine, you won’t be driving the tube very hard during the conditioning.

4) Electronically defocus the tube, so that the image on the face of the tube is defocused as much as possible. (this is important, you need to defocus the tube electronically, optical defocusing of the image on the screen will not work for you) Run the focus control of the set to min or max, whatever defocused the tube the most. Put on sunglasses and look directly into the tube to make sure that the image on the face of the tube is now blurry.

5) Select the AVIA disc to produce an all white screen (100IRE) and make sure that the 100 IRE message on the screen is disabled (turn off the subtitles), or you’ll burn a fuzzy ‘100 IRE’ into the phosphor.

You should now have an all white image displayed on your screen. Freeze frame this screen or use the A-B loop function so that this all white screen remains on the screen. If you have only replaced a tube or two, you can disconnect the applicable R G or B signal to the tubes that you have not replaced, no sense in lighting up the tube face of tubes that work fine.

6) Turn the brightness and contrast down to 30% each. Run the all white field like this for a full 24 hours, then bump up the contrast and brightness by 5% each every 12 hours after that. Keep increasing the brightness and contrast by 5% until you get to 60% brightness and 60% contrast.

7) The Tube Conditioning is now done. Reduce the height and width back to normal, reset the focusing of the set to normal, reconnect any R G or B cables that you took off to disable them, and enjoy your new tube(s). Do a color calibration if required. That’s it!

Did you find this information useful? Please consider making a donation to help defray the cost of managing and hosting future articles, tips, and documents.     

Or purchase from and a small percentage automatically goes to support this site at no extra cost to you! Visit their Blu-ray and DVD stores for sales. Want to show off your home theater? See our Blu-ray Release List & Must-Have Titles. Shop at and support our site!



Copyright All Rights Reserved.