Slight Blue Tint with Color Down

[Outland]

I picked up a lightly used Panasonic set (CT-20S10S) with the same chassis as mine (CT-20S2S) as a potential replacement CRT. They are the same TVs, except the new one has composite input. They have the same remote and menus.

My old CRT is a little tired, with slight burn-in from closed captions and a slightly dim top right corner. With color all the way down, the image is black and white, maybe a very very slight green tint (maybe).

On this new one, there are no dim corners, no burn-in, and the image is significantly brighter and a little sharper.

However, with color all the way down, the new one has a slight blue tint. What is the reason for this? I can't imagine it's more worn than the old one, which doesn't have a tint with color down. Is this how the set was when new?

[dieseljeep]

Originally Posted by Outland

I picked up a lightly used Panasonic set (CT-20S10S) with the same chassis as mine (CT-20S2S) as a potential replacement CRT. They are the same TVs, except the new one has composite input. They have the same remote and menus.

My old CRT is a little tired, with slight burn-in from closed captions and a slightly dim top right corner. With color all the way down, the image is black and white, maybe a very very slight green tint (maybe).

On this new one, there are no dim corners, no burn-in, and the image is significantly brighter and a little sharper.

However, with color all the way down, the new one has a slight blue tint. What is the reason for this? I can't imagine it's more worn than the old one, which doesn't have a tint with color down. Is this how the set was when new?

If you have darkening on one side, check the 4.7mfd 315 cap on the CRT board or nearby.

[old_tv_nut]

Slight tint of color with color control minimum probably just means it needs a slight color tracking adjustment.

[Outland]

Even on a 1994 TV? That would probably be in the service menu.

[old_tv_nut]

Ooops - mixed up my threads - sorry

[Outland]

So how do I adjust the color tracking? Watching a black and white movie reveals the slight blue tint as well.

[old_tv_nut]

Sorry, maybe someone else here knows how to find the service info or access the service menu if that's what it takes.

[Outland]

Here is what the service manual says.



This is a little overwhelming. Which of these settings controls tint (regular menu tint has no effect)? How do I jump FA1 and FA2?

[old_tv_nut]

You do not want any of the DAC (B) mode adjustments. You want the CRT (C) mode adjustments. Do you have a page showing them and telling their names?

Do you have a diagram showing the location of FA1 and FA2? Are they close enough to bridge with a screwdriver, or do you need a wire/jumper wire with alligator clips?

[Outland]

Do you have a diagram showing the location of FA1 and FA2?

Yes, here is the location of FA1 (N/2) and FA2 (N/3). Looks like they are down by the tuner. I will take off the back, jump them with alligator clips, then turn the set on and follow the directions to enter serviceman mode.

You do not want any of the DAC (B) mode adjustments. You want the CRT (C) mode adjustments. Do you have a page showing them and telling their names?

Are you referring to this table?



Thank you for the help. I want to carefully do this adjustment because I like the TV.

[old_tv_nut]

Yes, that table. Follow the instructions for C1 through C5 to get rid of any tint to the monochrome picture.

[Outland]

Will do. Thanks so much.

[Outland]

Is there a good test pattern to use for color tracking adjustment? I have a video essentials DVD somewhere.

[old_tv_nut]

A gray scale (steps) is best; color bars with the color turned all the way down works too, or you can even do it with regular programming with the color turned all the way down. (I don't know if your set automatically turns the color down when you are in CRT adjustment mode, but that would make sense.)

As the instructions state, go for a gray picture with no noticeable tint.

[old_tv_nut]

Off to bed now - good luck