iMac A1418 w/ Board #820-3302-A bklt_boost shorted to gnd

[slamacchia]

Hello, and thanks in advance for your help. This is my first post, and my first time working with schematics and boardview, in case I'm not on the right path. I'm troubleshooting an iMac with no display after sleep. Display has good image w/o backlight.

I replaced three burnt 2.2uF caps (C9793 C9710 C9712) and replaced without improvement.

I see some damage to the layers which surely broke some vias, but I don't know how to handle this.

I measured the following:

• F9700 is not blown
• Q9702
  • pins 1,2,3 = 11.9v
  • pin 4 = 11.83v
  • pin 5 = 0.01-0.06v

I cannot find U9100/U9000 on boardview. Does U9100 create BKLT_EN on pin 4?

• U9700
  • pin 4 = 0v
• TPP[1]BKLT_GATE = 0v

Where do I go from here?