BARCO 801s G convergence problem



I have a problem with my projector, a Barco Graphics 801s.

When I start the convergence procedure, I have this problem:
if I adjust the centre lines, the sides appeare completely shifted to the right;
(See first picture in the attached file)

When adjusting the sides, the center is completely out of convergence
(See second picture in the attached file)

Using the standard procedure it's impossible to adjust the left side.

With the blue, the problem doesn't occur.
I changed both drivers and output convergence boards, but the problem remain.

Someone knows where these problem come from and how to solve it?

Thks in advance.



  • gird_.jpg
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Well-known Member
Hi there,

Odd...convergance starts with the centre and sprials outwards, so you start with the centre, then just right of centre, just left, just above, just below, out 1 again etc.

Convergance is an iterative process, you can not do it in one pass, and probably need 3 or 4 times round the 'loop' to get a reasonable convergance, as the zones interact.

I find it useful on the first pass round to move it 1/2 or 2/3rd towards the correct setting for that pass as a king of loose or rough atempt, just to get the zones evened out as trying to get it perfect first time usualy ends up with you chasing odd errors.

The exception of course to this is the absolute centre which isn't so much convergance, but is a raster shift, which should be correct from an earlier part of the installation routing where you centre rasters, then align the physical guns using the + patern.


Mad Mr H

Novice Member
Picture on their side so a little difficult to tell..............

Your Horizontal mid line, top and bottom appear a little bowed.

Vertical looks good.

Picture ONE is correct, 2 is NOT.

ALWAYS work on the center area first.

Picture one looks as it should, I think your PJ is floor mounted ??? im tilting my head to do this !!!!

The blue you say is perfect.......I would expect a similar looking blue BUT out the other way.

This looks right if you ONLY have installed and basic geometry, PRIOR to convergence.....

Things to check are

1. Width coils correctly setup.
2. raster centered
3. installation menu followed with the "+" alignment
4. basic geometry

in the above order, PRIOR to convergence

I hope that is some help. Post a picture of the blue as well...............

You did midpoint everything prior to starting?

It looks pretty good so far........just take your time.................


Thank you for your replies,
The projector is table mounted.

The pictures were taken before starting the installation procedure because I had the camera at hands, obviously I started the convergence after having set the geometry.

The fact is that even iterating the guided procedure I reach “end of adjustment” when aligning the left border and I have to stop.

Following the convergence procedure, after having shifted the red raster so that the red grid converges on green (actually a very little shift is needed), I’m asked to adjust the middle left area, and I have to push the red a little to the left, but next step (left border) the red is so misaligned that the control is almost at 85% of its range when the red is correctly converged.

Once the last area I’m asked to adjust is done, I reiterate the procedure but at this point, when I arrive at the left border areas I always reach “end of adjustment” before the red converges!!!

From your answers, you’ll leave out any problem in some board, that consoles me!
So it seems that I have missed something in the set up procedure (or made some mistakes), but with the blue which I deal the same as the red, I have no problem, it converges perfectly after a couple of iteration!

Anyone had heard of similar problem before?


Barcoing Mad

Well-known Member
If your mechanical set up is good, i.e. tubes toed in correctly, rasters at mid-position, then the centre of your image should be converged with no need to move it using convergence controls.

Also overall red width needs to be set using adjusment coil, not pushed using convergence controls.

If you turn off (=50) all convergence controls, how do the red/green rasters appear?

Convergence ideally is a tweak to rasters which are already of the same size and sharing the same centre.

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