No blue in picture WS 55111

[damira]

The original problem was no blue in picture. Then convergence went out.
I replaced convergence chip and most caps on convergence board and 7 caps on module power supply.
I also checked the cv output resisters and general condition of board OK.
It has a good clear picture except still no blue in picture. The crt's all have color but the blue is not being processed to the screen.
Could someone give me a 123 of other likely conponents to check ?.
Thanks in advance !!

[lcaillo]

It is not clear what you mean by "blue is not being processed to the screen." If the blue CRT is lit, what is it lit with? What conditions, i.e. what signals, menus, PIP, resolutions, formats, inputs show the problem?

[damira]

Thanks for your quick response!
The CRT's are lit with red,green and blue light. On screen,things that should be blue are green. There is no blue color in any picture in any format. When I try to use convergence in settings, only red can be adjusted. The word blue is not even showing in this menu nor can it be adjusted. I've read that this would indicate a bad IC but the new one seems to work just fine.
One other observation, a muted blue screen can be seen momentarily when changing channels where you would normally see black.
I suspect another component is causing the problem because the blue crt is showing blue.
I really apreciate the help in this forum!
Thanks again

[lcaillo]

What do you see with a gray scale pattern? With color bars?

What you are describing has nothing to do with a convergence IC.

[damira]

Is there a diagnostic built in or do I need to buy a DVD and what should I look for?. I agree that this
problem has nothing to do with the convergence IC other than it preceeded the convergence problem.
I was hoping you could tell me what other part of the circuitry or processing would you suspect to be the problem. Have you seen this or similar problems before and what parts did you change?.
I appreciate you trying to help with the understanding that it is very difficult to diagnose technical problems without hands on.
Thanks again

[lcaillo]

The only test pattern built in is crosshatch for convergence.

You have to diagnose the problem clearly and identify the conditions carefully before one can even guess at where the problem might be, then you will need to do some signal tracing with a scope, most likely, to isolate the problem. Otherwise you will be able to do little more than "shotgun" the problem by randomly changing parts.
I cannot lead you though the troubleshooting and repair process step by step. This forum is limited to known symptom-repair relationships that have easy fixes. If you need troubleshooting assistance beyond that you can contact a pro locally or contact me directl for consulting for a fee. If you want help here, the problem needs to be better defined before I can even make a guess at where to point you. Based on what you have given me, I cannot tell whether the problem is in gray scale or in color processing. The performance with a gray scale pattern and color bar pattern will at least do that.