problem with convergence of 50HX81 (1 Viewer)

[Jody Carbone]

I recently purchased alignment template, so this was the perfect rainy morning to begin correcting minor geometry problems. I first did mechanical and electrical focus adjustment, then placed the grid on my screen.

With the TW series, I was able to pull up built-in geometry grids - cross hatch, center cross, etc, by going into service mode, then using TV/VID button on remote. I can't seem to get this to work on the 50HX. I have removed all inputs to VIDEO1, and still am unable to get these alignments. Can someone post the exact steps to get into service mode and call up these screens?

Without center cross pattern, I decided to do convergence and realign center in alignment mode (was only off by less than 1/4 inch). During convergence, blue grid is now shimmering to the point that it is impossible to do a good convergence alignment. It jumps from left to right - vertically it seems sound. I suspect this might have something to do with centering magnet because of its movement, but I am not sure.

Anyway, I tried as best I could, and have gone in several times. Each completion of alignment and Touch Focus produces a Touch Focus Error, and each time I re-enter convergence mode both red and blue are off. Touch focus may have something do do with overscan - once I got convergence close using grids, on NTSC sources (satellite receivers on VIDEO1 input) right side of screen has no picture (about 1 inch), so I pulled up Avia overscan grid and readjusted width to 5% overscan. Does this sound right? Shouldn't the picture be right on if using a convergence template? It makes no sense that my picture would be so far off-center.

I am concerned that the jumping blue grid will have a longterm effect if not remedied. Any help that can be given would be most appreciated.

Thanks much.

 

[JohnnyG]

Jody, none of those test patterns exist in the TV any more. It may still mention them in the service manual, but they've not been in the TV since last model year.

For Touch Focus to work properly, the screen has to be centered almost perfectly. If you're using a DVD player for this, it's possible that your player itself is not outputting a properly centered picture.

As for the jittering lines, that does not sound good! If you can see this jittering in video too, then it sounds like something bad has happened to the convergence system.

 

[Jody Carbone]

John,

Thanks much for the reply. The blue grid shimmering started just after I began to adjust convergence. I used HIT, WID, VLIN to match as closely as possible with the convergence grid, then started convergence with blue (at the time wasn't aware of the change in keypress to turn off blue [CHAN RTN]), and it started to shake back and forth.

I will spend more time and readjust parameters, tighten edges, etc. and see if I can get convergence to behave correctly.

I appreciate the tip on internal patterns - it was driving me crazy!

JC