Hello,
An LG 43UM6910PUA was donated to me. The backlights turn on and the voltages on the power supply are good. The mainboard appears to leave standby but the LCD stays off.
Disconnecting the right-side LVDS ribbon cable turns one half of the LCD black. Now if I measure voltage at the AVDD test pad on the connected left driver board, I get 17V.
If I re-connect the right LVDS cable, then the AVDD test pad on both of the driver boards goes to 0V. If I only connect the right-side LVDS cable, then the right driver board's AVDD test pad is still 0V.
With my + probe on the LOCK test pad (the only pad above the LVDS connector in the blurry pic [sorry]) on the faulty right-side driver board, I can see the voltage jump to ~3V and then AVDD goes to 0V. The ~3V is only an estimation since my multimeter isn't fast enough to measure it.
I tried taping off the CLK pins, they're the left-most 4 pins on the LVDS connector (again in the blurry pic [sorry]) but no difference.
Would appreciate any further guidance to dig deeper in this.
Thank you!
An LG 43UM6910PUA was donated to me. The backlights turn on and the voltages on the power supply are good. The mainboard appears to leave standby but the LCD stays off.
Disconnecting the right-side LVDS ribbon cable turns one half of the LCD black. Now if I measure voltage at the AVDD test pad on the connected left driver board, I get 17V.
If I re-connect the right LVDS cable, then the AVDD test pad on both of the driver boards goes to 0V. If I only connect the right-side LVDS cable, then the right driver board's AVDD test pad is still 0V.
With my + probe on the LOCK test pad (the only pad above the LVDS connector in the blurry pic [sorry]) on the faulty right-side driver board, I can see the voltage jump to ~3V and then AVDD goes to 0V. The ~3V is only an estimation since my multimeter isn't fast enough to measure it.
I tried taping off the CLK pins, they're the left-most 4 pins on the LVDS connector (again in the blurry pic [sorry]) but no difference.
Would appreciate any further guidance to dig deeper in this.
Thank you!
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