Video Problems: General Convergence Problems

Problems can occur with the convergence circuits, however the problem may not lie in the convergence board itself. Let’s look at a few of these, starting with the obvious ones:

V shift and size: All Barcos have the V shift and size controls located on the V board, that part makes sense..:). I’ve had vertical sections of the individual tube colors decrease or increase in size, to the point where the trimpots cannot bring the correct height back. A failure has occurred in a color’s V section, send the V board in for repair.

H shift: The H shift circuitry is on the focus/H shift board. A failure of a component can offset one or more colors by a small or large amount. Send the H shift board in for repair.

No convergence controls work: A fully functioning convergence section relies on a bunch of areas of the set working in conjunction with each other. The convergence power supply must work (which is located on the G2/diagnostic board on the 808/1200/1208/1209 sets), commands must be processed from the controller board going to the convergence board, and pulses from the HV section, V board and H shift board must all be present. Problems in any of these sections can cause a complete loss of convergence, and sometimes multiple boards must be sent in for testing to confirm exactly where the problem is.

No Pincushion/Keystone: The keystone and pincushion controls come from the V board. Failure of this section of the V board will cause these controls to be inoperative. Sometimes the H direction of key and pin will work while the V direction will fail.

I2R errors: Many data grade projectors use a serial set of commands from the controller board to digitally control various set functions. Barcos can display I2R error codes right on the screen, and those will indicate what digital control chip is not functioning. The service manuals show how all of the I2R error codes map out to each chip. Now, a couple of points to do it yourselfers. The Barco chips are very, let me repeat, VERY reliable, and failure of these chips is VERY rare. Usually some other component on the board fails, and causes the I2R error. Multiple I2R errors on the screen ALWAYS indicate problems elsewhere in the set, usually in a power supply section that drives the I2R chips.

Not all I2R chips are on the convergence board. Many other boards in the set also have these chips on them, and again, failure of the chips is rare.

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 Amazon.com and a small percentage automatically goes to support this site at no extra cost to you! Visit their Blu-ray and 4K UHD stores for sales. Want to show off your home theater? See our Blu-ray Release List & Must-Have Titles.