FIXED A1466 820-00165-A backlight problem

[isc]

I disconnect everything and replace charging board and its flat cable ,touch-pad fcc test other good working lcd assembly everything ok else no backlight when i close lid then open it backlight flashed then turns off
i replaced U7701 with new one
SMC_LID 3.3v
EDP_BKLT_PWM 2.49v
SMC_LID 3.42v
pin 3 for Q7707 is 0v now
what to test else?

 

[2informaticos]

"pin 3 for Q7707 is 0v now"
Was it before too; but you didn't get correct LCDBKLT_EN_DIV_L.
That's really strange.

Be sure to have good continuity between Q7706 and L7701; check R5490, if exists.

If backlight flashes one time, means U7701 boosts, but detects some problem and stops.
Usually XW7720 may cause this.
Check continuity from ball A5/U7701 to D7701's cathode.
Also check the value of all return resistors (R7717-22); be sure to have good solders and traces.

 

[isc]

the continuity between Q7706 and L7701 is perfect
R5490 not exist just track onboard
i replaced D7701 not fix the problem
i replaced L7701 the issue fixed!
L7701 swollen and expolded from the underside .