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Old 05-21-2022, 01:35 PM   #4
Maalobs
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Join Date: Jun 2016
City & State: Stockholm
My Country: Sweden
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Posts: 95
Default Re: Philips 70PUS7505/12 - Contrasts in image are echoed vertically upwards

Thanks for the reply!

I contemplated something like that, but I was expecting the problem to be isolated to either half of the panel in that case.
It's consistent across the entire screen, and there is no "glitching" in the artefacting, it's completely static and only follows changes in the video source.
So the artefacting is completely still when the video is not moving, for example in menus.
But this type of problem in the T-CON can appear in this "static" way too, you say?

I remember reading a comment some time ago about what the tape-solution does, if I recall correctly it's a matter of feeding power simultaneously from both ends of (vertical?) lines across the entire panel to power the LEDs on those lines.
If there is a problem with the power output from one side in that it can't maintain the voltage or supply enough current, this affects the entire line with interference.
The tape is then used to mask away the power delivery from the detected bad side, so that the good side can supply power to the entire line without interference.
Is my understanding correct?

The T-CON board is not covered at all in the service manual.
The best there is, is a description of the CN408 connector between the SSB and T-CON on page 9-4-8, but there is nothing about the connectors from the T-CON to the panel, where I understand the tape has to be applied.
How do I find out which pins to mask on the connectors from the T-CON to the panel?

Is there something that can be done on the T-CON board?
For example is this type of problem originating from a voltage regulator issue, maybe it's a crappy capacitor that has drifted out of spec or something?

This TV is 70" and in my mom's apartment so getting it out of there and to my house is out of the question.
An on-site investigation is possible but it won't be easy.
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