820-3332 no image on internal LCD

[MaxFix]

Hi there!

No water damage.
Image on external monitor but not on internal LCD. Tested with good new LCD - same.
PPVCORE_GPU - 0.9V
L9000 - 0.27V

PLease advice how to proceed.

Thanks!

 

[dukefawks]

Check when powering on if there is a pulse of 5V on L9000. Inspect for damaged caps/coils in the DP lines to the connector.

 

[MaxFix]

Pulsates from 0 to 0.27V then to 0V and 0.27V a few times on boot. Inspected DP lines everything looks in order. Did an ultrasonic clean, same.

 

[dukefawks]

LCD_PWR_EN coming high while turning it on, it will also be a pulse, so monitor while powering on.

 

[MaxFix]

No pulse on LCD_PWR_EN. Tried with a new working LCD.

 

[dukefawks]

See if it is shorted to GND. Any history on this, this usually does not "just" happen.