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Help Please Roland

Discussion in 'Projectors, Screens & Video Processors' started by fatrich, Jul 10, 2002.

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  1. fatrich

    fatrich
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    Hi Roland
    we chatted on the phone today about screen distance from the pj, and u ran through the proceedure for checking if there is enough adjustment on the pj so we dont have to move it.Unfortunatly i misplaced the piece of paper with my notes on can u run through it again please if u have time, and wot happens if the pj turns off when in the warm up screen, on last thing can i pin u down to a date for re callabrating and if this fails moving the pj.

    thanks

    richard
     
  2. Roland @ B4

    Roland @ B4
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    Richard no problem
    Bit of history and an overview to give others an idea of what this is all about.

    The reason for doing this is because Richard is investing in a fractionally larger screen and there is a possibility there is enough room on the tubes to expand the width without moving the projector back as would normally be required
    He bought a used BG808 from me nearly a year ago. Used projectors may have some degree of wear on the phosphor. Provided the same area is used when installed in its new home this is usually not a problem. If the image is expanded beyond the worn area then brighter sections will become apparent down the sides of the image as fresh phospher is used. A lot depends on the previous installers and how carfull they were in set up and PJ prosition.

    For the above reason it is possible that Richard's projector is slightly further back than normal. Wat he wants to check is whether the Pj doeshave to come back at all and if the tubes are usable for the new screen size in the existing possition.

    The procedure below is designed to make the projector use the whole of the phoshor area and some more. Any one elese reading or attempting the following should be careful an be aware that heating the seal around the adge of the tube can cause catastrophic failure and for the tube to impode. If you follow the below and keep the contast an brightness to a minimum and the time exposed to few minutes it should be OK.

    What we are doing is creating a block that goes way beyond the normal settings for the projector and exposese the entire CRT face. This should work for all Barco digital CRT projectors.

    Press the adjust key and go into random access. Select internal pattern. Chose a low resolution signal (15kz pal video will do the internal pattern will not affect your current settings and we will delete the block at the ned any how.) having selected the pattern come out of the menus and reduce the contrast and brightness to about 30 or 40 to a point where the image is perfectly visable but not bright. This has now created a new memory block for this pattern.
    Back into random access again Select the same internal pattern and go to the Geometry settings. adjust the Horzontal (H size) and Vertical (V size) to a point where they go right to the edges of the CRT tube and a bit more. Usaually you should be able to see this beyond your screen boarders but looking into the CRT may help. Don't worry about the shape of the picture.

    If the projector shuts down when you do this. I suspect the powersupply has been incorectly setup. Simply select your normal input and follow the proceedure below to delete the block.

    Having created our new memory block we need to find a way to use it to light up the whole of the phosphor. This can be done in two ways, both from the service menu.
    So into service menu chose either CRT warm up timer and switch the option on with the entre key. Or select CRT burn in and follow the on screen instructions. The Warmup will produce a constant white for 20mins. The Burn in (My favorite) will flash a white screen every 10 seconds or so. I prefer the latter as it doesn't cook the tube as much. Keep this exposure down as much as you can to prevent heating the seals of the tube.

    With the above you should be able to establish how far the phosphor extends beyond the edges of you screen. Pay attention to the top of the screen mainly as this is where it will be narrowest. Use a big sheet of white paper (4 sheets of A3 joined) to establish if there is a difference in brightness btween the old edge of the screen and the new. If the differnce is significant we may have to talk about changing tubes. (Richard yours can now be reworked)

    Deleteing the block
    It would be a well to get rid of this memory block just in case.
    Adjust key to get to Service menu, select Delete a block (Memory management on some). Make sue the block that you are about to delete is the internal pattern and press enter. You'll get a warning if you are sure Enter to confirm. Gone.

    That's it.
     
  3. fatrich

    fatrich
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    Thank you Roland for that i have printed this off and be giving it a shot tonight, will let u know how i fair up


    cheers

    richard
     
  4. fatrich

    fatrich
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    Roland
    started to read your instruction which are very clear, but to be honest i have a fear of shagging the pj if i try, so if its ok i will wait for u to do it can u firm me up a date please so we can re calibrate it and move it if necessary

    cheers

    richard
     
  5. Roland @ B4

    Roland @ B4
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    So I explained it over the phone and you lost the bit of paper.
    I spent ages typing it out and now!!!!!!!!!!!!!!!:eek:

    I'm coming north next week to sort out few issues. I'll let you know.
    Roly:)
     
  6. Pzycho

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    Sorry to butt in :)

    Up north next week 'ey? Are you fully booked, or would you be able to fit in a 808s install at all?
     
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