Phillips LCD - Static on A/V source

[Diah]

Re: Phillips LCD - Static on A/V source

I think you're right. Just found another source that uses av and picture is clear. Should have tried before but didn't think it was a source issue.

Do you think those av to hdmi upscaler converters would clear it out?

good to hear you had proofed its source issue.
any HDMI upscale converters with out source power supply could do good jobs..

converters with out out source power are useless.

[caphair]

Re: Phillips LCD - Static on A/V source

I think you’re right. Just found another source that uses av and picture is clear. Should have tried before but didn’t think it was a source issue.

Do you think those av to hdmi upscaler converters would clear it out?

[caphair]

Re: Phillips LCD - Static on A/V source

sure.. TVs brands / firmware design handle AV signal in different ways.
play with your source signal setting as i mentioned above.

Just tried there are no settings from the source. It's a handheld nintendo emulator type with games. No settings to adjust

[Diah]

Re: Phillips LCD - Static on A/V source

But the same source on another tv looks clear. Could still be a source problem?

sure.. TVs brands / firmware design handle AV signal in different ways.
play with your source signal setting as i mentioned above.

[caphair]

Re: Phillips LCD - Static on A/V source

from his first photo of the AV source the menu text look clear and the noise at JPEG back ground. its tell the problem at the source not the set. out put signal from the source need to change between YGBR to RGB. also the resolution of the signal... and all screw of boards chassis need to be in place too.

But the same source on another tv looks clear. Could still be a source problem?

[caphair]

Re: Phillips LCD - Static on A/V source

That interference does look like the video signal ground is missing. When component video is selected, did you plug the video signal into the Y or green component input jack?
The video signals go from the a/v jack board to CN702, through the power supply board traces (no components) to CN302 which connects to the digital board, and goes through a 0Ω resistor and a .1µf cap and into the Zoran ic.

I tried both Y and green in component and no image from either one. If I ohm test ground of av connector to ground of board and chasis it's 0 ohms

[Diah]

Re: Phillips LCD - Static on A/V source

from his first photo of the AV source the menu text look clear and the noise at JPEG back ground. its tell the problem at the source not the set. out put signal from the source need to change between YGBR to RGB. also the resolution of the signal... and all screw of boards chassis need to be in place too.

[R_J]

Re: Phillips LCD - Static on A/V source

That interference does look like the video signal ground is missing. When component video is selected, did you plug the video signal into the Y or green component input jack?
The video signals go from the a/v jack board to CN702, through the power supply board traces (no components) to CN302 which connects to the digital board, and goes through a 0Ω resistor and a .1µf cap and into the Zoran ic.

[caphair]

Re: Phillips LCD - Static on A/V source

Don't you have the service manual for this tv? It sure looks like the video ground is not making contact, If you pull out the video plug so the rca ground is not connecting does it change the interference? I can't see why you can't get a video signal on the component input. that would also check a different input that comes from the a/v board

If I pull out the video plug where the ground isn't connected the interference does change but still not clear. No video signal when I try on component input. Do you think it's related?

[R_J]

Re: Phillips LCD - Static on A/V source

Don't you have the service manual for this tv? It sure looks like the video ground is not making contact, If you pull out the video plug so the rca ground is not connecting does it change the interference? I can't see why you can't get a video signal on the component input. that would also check a different input that comes from the a/v board

[caphair]

Re: Phillips LCD - Static on A/V source

Ah ok. Yes having all screws on and tight causes no difference. I’m about to just order an ab to hdmi converter for $10 and call it done I think

[R_J]

Re: Phillips LCD - Static on A/V source

Most tv's these days don't have a mains ground, That is not your problem, if it was, don't you think it would also effect the hdmi and rf input also.
Have you tried installing the power supply/inverter screws to see if that has any effect on the interference?
Any filtering in the a/c input circuit is to prevent noise coming OUT of the tv's switching power supply.

[caphair]

Re: Phillips LCD - Static on A/V source

I noticed this tv’s mains plug doesn’t have a ground plug. Would that cause noise? Though I doubt it would be designed without a ground plug without filtering noise through the inputs

[R_J]

Re: Phillips LCD - Static on A/V source

All inputs are switched and processed by ic3301.

[caphair]

Re: Phillips LCD - Static on A/V source

Use the same source that is giving you the picture on the video input.
Have you tried the VGA input?

Yes it's the same source I'm using. No haven't tried VGA input. Do all these inputs use their own voltages or are they shared?

[R_J]

Re: Phillips LCD - Static on A/V source

Use the same source that is giving you the picture on the video input.
Have you tried the VGA input?

[caphair]

Re: Phillips LCD - Static on A/V source

Try the component input, You can switch the TV input to component and just plug the source video into the green input, that should give a green only picture. and see if the interference is still there.

Actually tried that before and get no picture at all. Not sure if it's the source I'm using or not

[R_J]

Re: Phillips LCD - Static on A/V source

Try the component input, You can switch the TV input to component and just plug the source video into the green input, that should give a green only picture. and see if the interference is still there.

[caphair]

Re: Phillips LCD - Static on A/V source

Visually checking all connections to the a/v board. Solder joints all look good too. I tried removing the ribbon cable and cleaning the contacts but that didn’t do anything.

[R_J]

Re: Phillips LCD - Static on A/V source

By A/V I will assume composite input or S-Video, So if hdni is ok, then the fault is not likely on the digital board (top right board). I would start by checking if you are missing a ground between the a/v board and the main/power supply board
If the problem is with the VIDEO input, check the trace for in the signal path, maybe there is a poor connection on one of the ribbon cables between the boards
If there is a poor ground for the video board, you will be picking up noise from the ccfl high voltage circuit which will interfere with the video signal.