PT-50LC14 convergence problem

**Duane122660** · **09-21-09, 05:31 PM**

I am working on a 3-chip LCD based RPTV. I have taken the light engine apart and cleaned the mirrors,lenses and LCD chips. After I reassembled I had all kinds of problems with the picture. I have replaced the LCD drive circuit board. It is now working close to normal, except for convergence.
The red color is slightly trapezoid one way and the blue color is slightly trapezoid the other way. I cannot get it corrected by moving the LCD chips themselves. I have the repair manual, but cannot find the menu to adjust the convergence.
Is there a way to electronically adjust the convergence on this TV ?
And is there convergence chips in this TV ? And where might I find them ?

Duane

**lcaillo** · **09-21-09, 09:19 PM**

Convergence in this type of set is purely mechanical. There will likely not be any electronic controls.

**Duane122660** · **09-22-09, 02:17 PM**

Icaillo,

Thanks for the reply !! I was afraid of that. It couldn't be easy.
Any suggestions on how to realign my TV ?
I have already left off as may pieces as I can, so I can get to the three LCD chips to fisacally move them while the TV is on.

Duane

**lcaillo** · **09-22-09, 02:58 PM**

I could guess at it, but without the unit here, my suggestions would be just that, a guess. The first thing that I would do is consult the service and training documentation on the unit. I suggest you find that if you can.

**Duane122660** · **09-23-09, 07:21 PM**

I got my convergence problem corrected yesterday!
I kept the screws holding the LCD chips loose and applied contact cement to the sides of the chips. Using a camera pointed at the TV and zoomed in on verticle and horizontal lines and computer display to easily see what I was adjusting. I was able to move the chips around before the glue dried.

What I thought was trapazoidal lines was actually parallel angled lines.

I don't recomend removing the LCD chips from the frame holding them, especially this TV. There are no scews for making adjustments!

Duane

**lcaillo** · **09-24-09, 09:04 AM**

You are lucky that you had an adjustment at all. Many of the most recent LCD systems have had the panels bonded to the prism and you can't move them at all. Most others have set screws and little notches to insert a screwdriver to apply pressure one way or the other. They are difficult because as soon as you tighten the screws you sometimes move the panel. The alignment is critical so it is often a process that you have to repeat several times to get it right.

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