Hi, hoping for some views on this one which I've not come across before. The TV generates an image that has 12 noticeable bands across it. The image is still there and accurate, but the colour (or perhaps the brightness) changes gradually across each band which creates a noticeable 'step change' at the edge of each band. Given it's a 4K TV with 2160 rows of pixels, I'm guessing the 12 bands correspond to 12 gate drivers of 180 rows each. If this guess is right, then perhaps:
a) all the gate drivers are malfunctioning the same way (which seems unlikely), or
b) the Tcon board is malfunctioning, or
c) something else
My guess is b), do folks agree? I'm not sure what Tcon malfunction would cause this effect. Maybe not enough power to the gate drivers so the image fades out as it works down the rows?? Which makes me wonder whether if the power board could be the culprit instead...?
The other thing that might be relevant is that moving images suffer from some degree of retention. So that prior images seem to remain faintly in the background for a little while. Does this imply a problem with the clearing voltage from the Tcon? 15,000 hours on the panel (see service pic) seems a lot but what I read says it should last 40,000+ hours
I've also attached the TV's Service page. It doesn't seem to suffer from the banding, which is curious. It shows some recent errors associated with the TV tuner, but I doubt if that is related to the image issue, which is the problem I want to fix. There are also some very old errors (2015, 2017, 2020) which can most likely be ignored.
a) all the gate drivers are malfunctioning the same way (which seems unlikely), or
b) the Tcon board is malfunctioning, or
c) something else
My guess is b), do folks agree? I'm not sure what Tcon malfunction would cause this effect. Maybe not enough power to the gate drivers so the image fades out as it works down the rows?? Which makes me wonder whether if the power board could be the culprit instead...?
The other thing that might be relevant is that moving images suffer from some degree of retention. So that prior images seem to remain faintly in the background for a little while. Does this imply a problem with the clearing voltage from the Tcon? 15,000 hours on the panel (see service pic) seems a lot but what I read says it should last 40,000+ hours
I've also attached the TV's Service page. It doesn't seem to suffer from the banding, which is curious. It shows some recent errors associated with the TV tuner, but I doubt if that is related to the image issue, which is the problem I want to fix. There are also some very old errors (2015, 2017, 2020) which can most likely be ignored.
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