I haven't been able to narrow down the source of this issue yet, and it's somewhat hard to describe but I'll do my best.
The TV powers up and works fine for a couple minutes. Then the screen appears to get dimmer. It is NOT the backlight. I've taken the TV apart and viewed the backlight from behind the screen where there are a couple holes that are illuminated and it does not get dimmer. So I've ruled out the inverter and bulbs.
When I look closer at the screen I see when it's normally working all the pixels appear to be lit. When it gets dimmer it appears that only every other column of pixels appears to be lit, and at times it even appears that they are shifting which ones are on and which ones are off by one column, as if the image were vertically interlaced.
The update rate also appears to decrease significantly. Sports shows can get blurry in high speed motion when the issue is present.
If I have the menu up prior to the issue happening and then it starts going bad and I close the menu I get somewhat of a ghosting effect, where the "off" columns don't appear to have turned completely off.
I'll try to get a picture if at all possible, though getting a macro shot of individual columns might be hard.
So far I have disassembled the TV down to the panel and probed the voltages where I would expect there to be 3.3V, 12V, 24V, etc. and everything appears to be good when it's both working and not.
So I'm left guessing if it's the T-CON board, maybe the main board not transmitting a good LVDS signal, or maybe even a bad power supply I haven't found yet. I haven't gone as far as borrowing the 1GHz scope from work yet, but it may come to it. The service manual I have only has a schematic for the main board, and it's the typical "if this doesn't work replace board X" type manual.
The TV is still watchable, but definitely dimmer and less high-def in its current form. I'd like to return it to its proper state though if possible. Any help is appreciated.
The TV powers up and works fine for a couple minutes. Then the screen appears to get dimmer. It is NOT the backlight. I've taken the TV apart and viewed the backlight from behind the screen where there are a couple holes that are illuminated and it does not get dimmer. So I've ruled out the inverter and bulbs.
When I look closer at the screen I see when it's normally working all the pixels appear to be lit. When it gets dimmer it appears that only every other column of pixels appears to be lit, and at times it even appears that they are shifting which ones are on and which ones are off by one column, as if the image were vertically interlaced.
The update rate also appears to decrease significantly. Sports shows can get blurry in high speed motion when the issue is present.
If I have the menu up prior to the issue happening and then it starts going bad and I close the menu I get somewhat of a ghosting effect, where the "off" columns don't appear to have turned completely off.
I'll try to get a picture if at all possible, though getting a macro shot of individual columns might be hard.
So far I have disassembled the TV down to the panel and probed the voltages where I would expect there to be 3.3V, 12V, 24V, etc. and everything appears to be good when it's both working and not.
So I'm left guessing if it's the T-CON board, maybe the main board not transmitting a good LVDS signal, or maybe even a bad power supply I haven't found yet. I haven't gone as far as borrowing the 1GHz scope from work yet, but it may come to it. The service manual I have only has a schematic for the main board, and it's the typical "if this doesn't work replace board X" type manual.
The TV is still watchable, but definitely dimmer and less high-def in its current form. I'd like to return it to its proper state though if possible. Any help is appreciated.
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