Hi,
I started posting in a different thread and I was told it was not the best ans the tv model and the fault did not match. I am copping here what I wrote.
After starting the TV it works ok for a few seconds and then starts showing ghost image with horizontal lines intermittently (except the very top). The frequency of the ghosting is steady, like every second or so, it goes from normal to ghosting every second and back.
The TV is a 49XE8096. I already did quite a lot of trouble shooting. And I got the doubt if the problem is in the panel or de Tcon.
When disconnecting one side from the panel at a time. The right side works fine, but the left will only show a white screen.
- No shorted capacitors.
- The ghosting seems to go at the same pace as the VGH ODD and VGH EVEN changes
- ODD/EVEN change from -7.05 to 28V
- VST seems to be steady to -7
This is the troubleshooting I did:
- In the left panel board (the one with the flex cables) I remove the resistors connecting ODD/EVEN. All the screen was flickering with horizontal lines and some vertical bands. The I solder a jumper between ODD-EVEN-VON (28V) on the panel side (ODD/EVEN are disconnected from the TCON as the resistors were removed)... then the image is really good but there is a black line on the top (where the image was always ok at the beginning).
- With the previous situation, I also remove the resistor from the left panel board connecting a signal called VST (-7V). Then all the screen (except the top part) has horizontal lines (no ghosting), very obvious lines. Then I disconnected ODD/EVEN from VON (28V) and connected it to VDD (15V). Then the horizontal lines became thinner and much lighter, noticeable but not much. And the black line on top also became thinner but still black.
I know it looks like something is wrong with the panel. But my question is if someone thinks that there is still the chance that the TCON board could make this king of fault. I read many people with a similar failure (the starting point) but for them the ghosting was steady and not blinking like mine. I wonder is something can be wrong with the level shifter. I could not find the schematic for the Tcon Board, or the data sheet from the RT6937 that seems to be the reference voltage generator.
Thanks in advance... any help is appreciated.
Update: The vertical artifact band on the side are something new after I tried to reflow the RT6937.
I was advise to lower the backlight (not brightness) to see if image was coming back to normal, but it did not work.
I think there might be a crack on the RT6937 that I not sure if I made it myself when trying to reflow or it was there from the beginning. And I am not sure if all the problem can be caused by the RT6937.
I started posting in a different thread and I was told it was not the best ans the tv model and the fault did not match. I am copping here what I wrote.
After starting the TV it works ok for a few seconds and then starts showing ghost image with horizontal lines intermittently (except the very top). The frequency of the ghosting is steady, like every second or so, it goes from normal to ghosting every second and back.
The TV is a 49XE8096. I already did quite a lot of trouble shooting. And I got the doubt if the problem is in the panel or de Tcon.
When disconnecting one side from the panel at a time. The right side works fine, but the left will only show a white screen.
- No shorted capacitors.
- The ghosting seems to go at the same pace as the VGH ODD and VGH EVEN changes
- ODD/EVEN change from -7.05 to 28V
- VST seems to be steady to -7
This is the troubleshooting I did:
- In the left panel board (the one with the flex cables) I remove the resistors connecting ODD/EVEN. All the screen was flickering with horizontal lines and some vertical bands. The I solder a jumper between ODD-EVEN-VON (28V) on the panel side (ODD/EVEN are disconnected from the TCON as the resistors were removed)... then the image is really good but there is a black line on the top (where the image was always ok at the beginning).
- With the previous situation, I also remove the resistor from the left panel board connecting a signal called VST (-7V). Then all the screen (except the top part) has horizontal lines (no ghosting), very obvious lines. Then I disconnected ODD/EVEN from VON (28V) and connected it to VDD (15V). Then the horizontal lines became thinner and much lighter, noticeable but not much. And the black line on top also became thinner but still black.
I know it looks like something is wrong with the panel. But my question is if someone thinks that there is still the chance that the TCON board could make this king of fault. I read many people with a similar failure (the starting point) but for them the ghosting was steady and not blinking like mine. I wonder is something can be wrong with the level shifter. I could not find the schematic for the Tcon Board, or the data sheet from the RT6937 that seems to be the reference voltage generator.
Thanks in advance... any help is appreciated.
Update: The vertical artifact band on the side are something new after I tried to reflow the RT6937.
I was advise to lower the backlight (not brightness) to see if image was coming back to normal, but it did not work.
I think there might be a crack on the RT6937 that I not sure if I made it myself when trying to reflow or it was there from the beginning. And I am not sure if all the problem can be caused by the RT6937.
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