820-3476 PP5VR3V3_SW_LCD missing

[ajdoc]

No image/backlight.
Got chime, fan spin...

PP5VR3V3_SW_LCD @ 0.0V

L8300 0.0V on both sides.

U8300/1 @5.15V
U8300/2 @0.0V

U8330/1 @ 0.0V
U8330/2 @ 0.0V
U8330/3 @ 0.0V
U8330/6 @ 0.0V
U8330/7 @ 0.20V
U8330/8 @ 3.33V

Any idea?

 

[2informaticos]

J8300 must get 5V at pins 28-30 at least in the first seconds, when machine boots; even if no LCD connected.
If LCD is connected, then pin 9 should rise to 2.5V and get 3V at pin 4/U8340.

 

[ajdoc]

J8300 pins 28-30 without LCD got 0.17V in first seconds, then 0V.
J8300/9 with LCD got 0.0V
U8340/4 got 0.0V

U8340/5 had 3.3V.
Replaced U8340 and U8330 and all good - thank you. SOLVED