Hi all,
bit of a weird one today,
Got this set with just backlight no picture, sound etc.. works fine so mainboard and PSU are likely good. I think it's a bad panel but don't know if it's fixable, here's why:
T-CON voltages all present when both LCD ribbons are disconnected but if both are connected then most of the rails are gone (ex. VGH, VGL, HVDD)
If only one of the ribbons is connected, I do get a hazy picture from the respective side but there is a loud hum coming from the T-CON board due to what I suspect is overcurrent and the circuitry that generates the VGH voltage get's very hot (100 - 120 C) and VGH drops from 25v to 22v and fluctuating, this is due to what I suspect is overcurrent from a bad panel.
I am confused by the fact that both sides of the panel display this behavior, how is it possible that the panel is bad on both sides? I've never seen a fault like this.
One other important thing to mention is that on both COF boards of the respective LCD sides there is a chip that get's very hot, the chip is the same part number on both sides and I couldn't find any dead shorts on the components around them. Anyone know what this chip is? it has markings AAT7212, I couldn't find much information on it.
Any insight is appreciated,
Thanks!
bit of a weird one today,
Got this set with just backlight no picture, sound etc.. works fine so mainboard and PSU are likely good. I think it's a bad panel but don't know if it's fixable, here's why:
T-CON voltages all present when both LCD ribbons are disconnected but if both are connected then most of the rails are gone (ex. VGH, VGL, HVDD)
If only one of the ribbons is connected, I do get a hazy picture from the respective side but there is a loud hum coming from the T-CON board due to what I suspect is overcurrent and the circuitry that generates the VGH voltage get's very hot (100 - 120 C) and VGH drops from 25v to 22v and fluctuating, this is due to what I suspect is overcurrent from a bad panel.
I am confused by the fact that both sides of the panel display this behavior, how is it possible that the panel is bad on both sides? I've never seen a fault like this.
One other important thing to mention is that on both COF boards of the respective LCD sides there is a chip that get's very hot, the chip is the same part number on both sides and I couldn't find any dead shorts on the components around them. Anyone know what this chip is? it has markings AAT7212, I couldn't find much information on it.
Any insight is appreciated,
Thanks!
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