820-02773-a A2338

[tipoti]

Device liquid contact
the customer disassembled the device and LP610 exploded. I replaced the LP610. The device turned on. It worked for 1 day, then the fan started spinning at full speed and would not turn on. When I checked, I noticed that the UC710 was also damaged by liquid and replaced it. There is currently a startup sound but no image. When I look at it with light, I cannot see the Apple logo on the screen.

LC710 : 2.2 volt
PPVOUT_LCDBKLT : No voltage
PPVIN_LCDBKLT_R : 13v
LCDBKLT_EN_L: 13v
PPVIN_LCDBKLT_Q : No voltage ( i change it QP800 but same problem )

 

[2informaticos]

"LC710 : 2.2 volt"
Bad; CC715 should have 3.3V.
No reason to check backlight circuitry, until get correct voltage there.
Compare diode mode to ground reading with good board.

Check all resistors (RC709-13) and traces from feedback network.

 

[tipoti]

I checked all the resistors. I changed the capacitors around it. The device gives 3.3v when it first starts up, it drops to 2.4 volts after 15 seconds.
I removed the RC412-13, it's the same, what else can I check?
I don't have a spare working card

 

[2informaticos]

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