Some things to check...

I start out securing the yoaks. Barco yoaks tend to be lose. I loosen the screw and move snug with the tube or put silicone sealer on the yoak. Try to wiggle your yoaks if they move its a source of drift. ( Barco was much better about this in the early models pree 1991 but got lazy later)

From my experience the way I like to do it is, I set the convergence to MID position in the service menu. Make all the settings Raster, Focus and All points at 50%. That means the projector is not using any electrical/magnetic voltage to alter the image. You also keep your convergence tray cooler. So you will have less convergence drift if you get your mechanical setups closer to 50 %.

I then try to get the picture as best I can at 50%. Focus etc by moving the focus assy etc. You need to use the base install menu frequency typically to adjust focus yokes because that is always factory as the install is before you adjust focus and you need that menu clear.

If you have too much point convergence on both sides of one color..

The H width of the tubes from center to outer edges is controlled a few ways.


The Barco has a High scan, Low scan section of the deflection yoke there is a small board that the deflection yokes plug into ( 12xx) if your width is too large ON BOTH SIDES on one color depending on the input frequency you have to tweak which color is off by adjusting this small board on the top of the cover. It’s best to use a plastic screw driver because these are inductor adjustable transformers and they will heat up your screwdriver. On the 808 it’s on your Mother board PCB.


Now the left side of the screen is adjusted on the Horz board there is H linearity a center and typically left side. There are two pots on the H board to adjust this if your boxes are too far apart or too close on one side.


On Vert Board their is also Vert Raster Size if you vertical is too large or too small on the vertical board. Typically you can adjust the RED and BLUE. The Base V Raster shift is also on Vert Board up down.
Focus- H shift board you can adjust the H shift left or right.

To MOD ...


On the Early 1200 models there is a 200 V cap in series with a resistor on the H Width board. This cap gets leaky and shorts so if you have a 1200 replace is CAP!

( on 1200 there are a couple of things to change too on the H board you need to change out a CAP on the Horz board that is on a riser board later on the 1209 1208 different topic)

Anyhow, Barco did a service update later on the 1208 1209 units and changed this with a 400V. But they had to switch positions, if you notice on your newer 1994-1999 unit you will have a Resistor but the symbol on the board is a CAP and where the cap symbol there is a resistor.

Now I noticed on the 1200 they used a very high quality resistor which keeps its value. But on the later 1209s 1208s 1209 1208 they had to swap the position of the resistor and the CAP. Because the CAP is 400 v and larger and had to use a resistor that stands up. (Some people call this a protection resistor)

If you measure the resistance of all 3 (RGB) you will see horrible values this stand up resistor is not sealed inside and tends to oxidize and heat up cool down causing drift.

To get a good picture stability, replace this resistor with a high quality metal film. I find it makes the picture much more stable on the later models.


I hope that helps.

I do this without thinking about it so to describe is hard sometimes

GREG